Hatred was supposed to be a familiar friend, the thing he'd cultivated from the moment of betrayal and propelled him into training, yet he'd still never felt it like this. It was strong, painful, and humiliating next to the horrendous gap in his strength compared to his brother's. He'd thought he'd been succeeding, been progressing far beyond the norm, was a genius but Itachi had destroyed that idea. He was weak, even more, Naruto was growing stronger than the breakneck pace Sasuke was supposed to be at. Naruto had defeated an enemy he hadn't had a hope in fighting. Naruto was who his brother was interested in. Naruto. Dead-last, loser, idiotic Naruto.
It couldn't be allowed, the wrath forcing his personality inwards, pushing the rage to the surface wouldn't let this stand.
"Fight me."
He was in hospital clothing, standing in the middle of freshly laundered sheets, and staring down what might be his only friend in the world with pure, abject, hatred.
The fight wasn't anything special, but was soothing. He knew this, knew Naruto, knew how to deal with his clones and his screaming and his endless stamina. He was keeping up because of course he was, Naruto was the one who should be struggling, should focus on keeping up. Sasuke was ahead of him, better than him, and would eventually be better than the man who'd taken everything from him.
Had to be. He had to be stronger, or else what would happen? Nothing. His clan's memory would stay unrested, their killer free to live a long life while they remained merely a tragedy, something for everyone to bury and forget about. The Uchiha would never be associated with strength or pride ever again, but just as victims. Victims let down by the one person who was meant to avenge them, to bring their killer to justice. He would be letting down his cousins, his neighbors, his auntie and uncle with the rice cake shop, his mom, his dad, his everyone. His life. Dead. Clan. Dead. There was no one left. Only him.
He was kicked into the air, but that made it easier to use a katon against the obscene amount of clones below him, clearing the hospital roof of false enemies so he could find the real one. It was a massive display of power, of prowess, and he still remembered his father's shocked face when he went from barely producing a spark to mastering the jutsu in such a short period of time, of how he praised him in a way that made him feel full and loved and alive-
There was a twisting in the flames, unusual for the jutsu, and suddenly the fire was disappearing in the whirl, blown away by the power accumulating in their center. Naruto and a clone were there, the twisting energy condensing into some sort of blue ball that even from above looked powerful, deadly.
He'd learned a new jutsu. Just like that, when Sasuke wasn't looking, when he was asleep because of his brother once again he'd learned and mastered a new jutsu to rival chidori.
Sasuke went to make chidori, no thoughts to how this jutsu would be just as deadly but only on how he needed to meet Naruto's challenge, to prove that he was stronger, that he wasn't slowing down, that he wasn't going to leave all the people he'd ever loved unavenged and die a foolish death fighting his big brother-
But he would.
He'd challenged Naruto to prove himself to himself, because Itachi had rocked his perception of his strength so much all over again. Itachi had won, had broken his arm and thrown him back into despair like it was child's play. Naruto had learned a new jutsu while he slept that was too strong, massively powerful and should be way too advanced for him. Sasuke had been his goal, but already he could see how Naruto would surpass him, and how that felt like more of a failure he could put into words. It meant more, meant he'd never be able to defeat his brother…and then what would he have left?
Naruto was glaring up at him, teeth barred, but seemed a bit…distressed. This wasn't the victory he'd wanted, and Sasuke knew that, he'd said as much at the beginning of the fight. He didn't want a fight full of hatred and insecurity but one where they respected each other. Naruto didn't know that was all Sasuke could give, that he'd been told if he truly wanted to be powerful enough to defeat his brother than he'd need to kill his best friend, which was looking like him. But how could he do that? Not even emotionally, logistically? Every time he thought he grew stronger Naruto grew infinitely more. One step for him was five for Naruto. He was- there was no hope.
He was never going to defeat his brother.
Chidori flared, then died in his hand, his heart not in it. Why fight a war he couldn't win? Why fight someone he cared about if it would lead to nothing? Why try to kill Naruto when he knew he never could?
What an absolutely pointless life.
When he started to fall into Naruto's jutsu Naruto's momentum brought him closer in a way Sasuke knew he wouldn't be able to stop. He wouldn't be able to evade his technique, could only defend, but staring at his angry yet distressed friend made him not want to try. He'd done this to him, had put him in this position, and worse yet might have killed him for power one day had things gone differently. Naruto was the genius, was the one growing too far and too fast. He deserved the win, even though it chafed, but that meant Sasuke was the loser. A loser couldn't defeat his brother. A loser could never avenge his clan. A loser just had to die.
In the end it wasn't an active decision, but a relief he let himself fall into. Naruto would hurt, sure, but he'd get over it. He was the winner after all, and would have ultimate proof to his abilities. He wouldn't let his dream die. He'd become hokage, and maybe as hokage would be the one to hunt down such an evil missing nin that was his brother. Maybe he'd avenge his clan. Maybe even in Sasuke's name. That would be nice.
Naruto's technique came too close, for his chest, and he saw how Naruto realized what was happening. His distress grew, but he couldn't pull his arm back, and Sasuke wasn't going to try a counter. It was over, the cool blue of Naruto's technique swallowing his vision and the swirling power making his ears ring. It was over.
He fell into Naruto's jutsu, and waited to die.
***
Kakashi didn't know what he would see on that roof, but he knew he had to watch.
It was information gathering, objectively assessing the personality and mental states of his students after a traumatic event. It was important that he not interfere until absolutely necessary, that he let them fight so he could read them, understand them, and then figure out an approach best tailored to what he'd learned.
But what he'd learned so far…wasn't good.
Sasuke was consumed, was playing off of Naruto's insecurity to goad him into a fight he didn't want. He was tense and angry, his eyes somehow both distant and intense as he kicked away Naruto's clones, his hits too brutal. This…was what he was worried about. He knew tsukuyomi could be brutal, had felt it himself not too long ago, and he didn't judge Sasuke for acting out but this…distance between his teammates couldn't be allowed to grow. If he shunted everything off to the side for his ambition then he wouldn't have anything left, and that was no way to live. He had friends who cared about him, if Naruto's distress was any indication. He was throwing his life away letting his revenge consume him like this.
But then he actually did throw his life away.
He could barely understand it. One moment he'd been held tense as he saw the rasengan appear in Naruto's hands, his mind cluttering as too many implications and memories tried to assert themselves. He was ready to intervene, preparing himself for the most ideal time to do so as no doubt Sasuke would meet the rasengan with chidori, would match Naruto's close-combat ninjutsu with his own in what was promising to be a spectacular explosion if Kakashi couldn't get to them in time, but even though Sasuke's hand sparked that was all it did. He looked up, let himself understand the emotion playing out in Sasuke's eyes like he had the whole fight only for him to falter, unable to process what he saw there. For the first time Sasuke was relaxed, limply falling into Naruto, his eyes deadened in a different way. Understanding, resignation, hatred, but also most concerningly relief. He was relieved.
An older instinct made him move, a fear built into him. Naruto was looking up at Sasuke in horror and complete lack of understanding. He didn't know what he was doing, only knew that it was wrong, that it would hurt. He didn't know what would happen to him afterwards, how he'd see his own hand through his friend's body, how he'd be stained red up to his elbow. He'd have to bear Sasuke's weight on his arm as he died, would hold his hand within the wound in an attempt to plug up the blood to try to save his life before someone would explain it was pointless, that he was already gone. He'd have to pull out his hand, feeling the mushy debris of his friend's insides as he struggled to free himself. Then he'd see Sasuke fall, see the blood pool beneath his body, see his relieved face, and know what he'd done to him.
Kakashi had always thought Sasuke was him, was a genius kid who'd been hurt over and over again. Now he saw himself in Naruto, saw his pain and his friendship pull him apart as he registered what was about to happen. Friend-killer. His best friend's cruel avenue for suicide.
And Sasuke was Rin. His friend who was about to die. Resigned to it. Ready for it.
Not again. Please god not again- not to Naruto-
He caught Naruto's wrist and flung him away, let the nearest water drum take the impact and didn't spare a moment to wince at the impact. Naruto would prefer the hit over what he'd been about to do, been forced to do.
He caught Sasuke in the air, pinned him flush to Kakashi's chest with his arms trapped so he couldn't fight or escape, his feet dangling from where he held him. Sasuke didn't try to escape, didn't try to fight, just let his head hang. It made Kakashi's stomach turn over.
Naruto was trembling when he looked over, his rasengan creating such a small outward impact where his hand touched the water drum compared to the waterfall of carnage on the other side. Naruto knew the technique, was looking at the residue of it with wide, horrified eyes. Maybe he wouldn't have had Sasuke's corpse to deal with. Maybe the rasengan would have left nothing of Sasuke. Maybe he would have destroyed his friend over killing him. He saw this in Naruto's eyes, the exact same torturous thoughts of what could have been, but didn't have the luxury of comforting him.
"Sakura," he barked, trying to let his brutal tone conceal the dryness of his voice. "Stay with Naruto."
He'd barely noticed her at the door of the roof, clutching it as she too came to understand what had happened. He watched her go to Naruto on shaking feet and pat his back, and let that be enough.
He took Sasuke away, took him into the trees so his friends couldn't see him, got a moment to breathe without him weighing them down, reminding them what he'd just done. When he went to put him on a branch he hesitated, and went deeper into the forest so he could put him on the ground instead. Sasuke wasn't fighting him, wasn't talking, and didn't look up when Kakashi settled him against a trunk of the nearest tree.
"Sasuke," Kakashi said, then stopped as he recognized the weakness of his voice. He cleared it, and tried again.
"Sasuke."
He levered his head up, but his eyes weren't alive. They looked through him, uninterested in what Kakashi had to say, all the fire and rage just gone. He didn't look suicidal, but Kakashi had just seen him try. He looked…
He didn't know this boy in front of him, couldn't rely on his own experiences to guide him. Sasuke was supposed to be the one he understood more out of any of his students, was supposed to be the one he could connect through based on shared horror and experience, could guide because Kakashi had been there. He'd never done this, had never tried to use his friend as a means to an end, had never given up. He'd been in the throes of despair so complete that only the mission had kept him going, but he'd still kept going. He would never do this. Never.
"I don't know how to help you," Kakashi gasped, and it was a new revelation to him, devastating. He'd thought he'd understood, but he didn't. Thought he could help, but he couldn't.
"Do you know what that would have done to Naruto?" he couldn't help but ask, couldn't help but go back to what he understood. "It would have ruined him."
He didn't even know what would have happened to Naruto, how this could have effected him. The gravity of such brutal grief and guilt was not something Naruto had ever had to deal with. Guilt would be something completely new to Naruto, and though he'd lost the sandaime, it couldn't compare to the grief of seeing your friend die in front of you. He might have been just as changed as Kakashi was, became just like him, all his brightness gone in favour of standing at a grave and aching for what could have been.
Sasuke snorted, and though it was clearly bitter there wasn't a lot of spirit in it.
"He'd be fine," he whispered, and pressed a hand to the tree to help him get to his feet. He didn't look at Kakashi, just started a slow walk back towards the village, the only indicator to his feelings how he wrapped his arms around his stomach.
"He would have been fine."
Sasuke was under suicide watch, and he needed to be.
He'd snarled and argued when he was confined to that particular part of the hospital for cases like his, but not enough to assure Kakashi that he still cared, still wanted to live. He was acting like himself, but less than himself. Maybe it would have been easier if he was different, acted like how every other committed ninja acted, but he was just him. It made Kakashi wonder if Sasuke had contemplated suicide before, was comfortable with a part of himself that just wanted to die. He'd had too much ambition before for Kakashi to think about it, but he should have seen the signs. He'd been to Sasuke's home, had seen the uncomfortable contrast of an almost sterile cleanness in his own room compared to obvious neglect in other parts of the house. He'd seen Sasuke falter and shake in fear at Zabuza's killing intent, knew he would have hurt himself to cut the tension if Kakashi hadn't spoken up. There were a lot of signs, but he'd ignored them all.
Why? Why would he ignore Sasuke's self-destruction?
Unfortunately Kakashi knew the answer to that. He ignored it like he ignored his own, trusted that it would be like his and that all it would do was make him a sad but competent shinobi. He'd wanted to help, of course, but the only remedy he knew for such a thing was friendship. Maybe that was trite but even though Kakashi himself had been destroyed by his relationships more than once it was still the thing that kept him going, kept life worth it. He had Gai, Tenzo, and Naruto to take care of even though he hadn't known Kakashi existed until just a little while ago. He had purpose and people, two things most necessary for life. Sasuke had had plenty of purpose, but no people, and Kakashi had tried to fix that, to give him a team he could grow to love and rely on… but he'd underestimated how important Sasuke's purpose was.
There were seals on the room leading to where Sasuke was confined, even though confined was a strong word. It wasn't a prison, and that's why they needed the seals. Sasuke could open the door or the window and let in the breeze, but he couldn't leave. He was visited only by ninja, civilian nurses not trusted to care for a potentially volatile shinobi. There was an agent from T&I that saw him daily for a much softer approach to psychology than what they usually dealt in, a huge deal since there was such a demand for their services after the invasion but Sasuke was valuable. Team seven visited of course. For ninja in such a state visits from friends and family were encouraged. The last thing Sasuke needed in this state was isolation.
(The last thing he needed when he was seven and traumatized was isolation, but that's what he'd gotten. If a seven-year-old snapped it didn't matter, but a shinobi could take people with them.)
Sakura saw him a lot, but was treating him noticeably different than before when he was in the hospital for physical reasons. Her good humour was more artificial, and more than once he'd seen her leave his room with a wave and a kind smile only to turn the corner in the hallway and sink to a sit, burying her head in her knees as she hugged herself. Sasuke treated her like he had before, ignoring her most of the time with derisive sneers thrown in whenever she demanded an answer. He didn't really speak to her (which was unfortunately in-character) but he spoke even less to the T&I agent assigned to him. The agent was a seasoned kunoichi and Kakashi had had high hopes for her, but every debrief she gave him was worse than the last.
"He doesn't respect me," she explained, looking at him seriously. "This doesn't work unless he respects me."
It was pointed, the idea being that Kakashi needed to step up, be the avenue on which to facilitate Sasuke's healing as his respected sensei. Little did she know the respect Sasuke had for him was purely conditional.
Naruto…
Even though Sasuke's suicide hadn't been successful, it had still shattered him. The mere idea that the rival he measured himself against could be weak was enough, but how he'd shown that weakness had thoroughly smashed any preconceptions he had about his friend. He never went in to see Sasuke, but he sat outside his hospital room more than any of them, just curled up in the nearest uncomfortable office chair with his head in his hands as he thought. When he wasn't outside Sasuke's room he was seeking out Kakashi, the only person he could talk to about this. At least he had one of his student's respect.
"Why?" he asked, over and over again, in many, many different ways. "Why would he…"
"…Sasuke's suffered a lot," Kakashi offered, keeping one hand on Naruto's back as he stared into the water of a small creek in the forest they'd chosen to meet up. It was a pitiful offering, and Naruto thought so as well.
"So what?!" he yelled, but didn't look up. "Everyone's suffered. He's not special."
Except Kakashi was beginning to believe he was, had suffered in a way that was. He could no longer empathize with him, and saw that same frustration on Naruto. Neither of them understood him anymore. He was lost to them.
"He just needs to try harder," Naruto spat. "Whining about his problems won't make them go away. He needs to just keep going."
Kakashi sighed, suddenly reminded of a similar speech Naruto had given young Inari in the land of Waves.
"I don't think he thinks there's a point," Kakashi explained. "What if there's no possible way for his problems to resolve? What if he just has to learn to live with it?"
Naruto choked, a jerky moment that had Kakashi clamping a hand down in his shoulder in concern.
"Then he'll die," Naruto said, his voice small. "He can't live with it, Kakashi-sensei. If that's the only option he'll just…he can't-"
He didn't finish the thought, and Kakashi carefully looked away as his tears fell into his lap, knowing how much Naruto didn't like for people to see him cry.
Kakashi visited him too.
"He's not fine," Kakashi accused, trying to get a rise out of his student even if it wasn't ideal. Anger was better than passivity. "He's been offered to apprentice under Jiraiya, but he's refusing to go while you're in here. Naruto's refusing to move on." He paused. "I'm sure you know what that's like. Imagine if you'd actually died."
"Sounds like his problem," Sasuke said with a shrug. He was still in his hospital clothes, sitting on his bed and facing the window like he didn't actually care if he ever made it out of there.
"Sasuke," Kakashi tried, then shook his head and fell back on old techniques. "If you want to get better you need to rely on your friends."
Friends and purpose, that was what he needed. Kakashi didn't know how to give him the former, but maybe he could make his friends his purpose like Kakashi had made his own.
"I don't want to 'get better,'" Sasuke mocked, but didn't say anything after that.
"Then what do you want?" Kakashi asked, restraining his own temper.
"You know what I want."
"Sasuke," Kakashi growled. "Abandon revenge. Focusing so much on your own vengeance is what got you here."
Sasuke's head jerked, and he knew he'd made a mistake.
"'My own' vengeance?" Sasuke asked, his smile curving bitterly. "You think this is about me?"
"Who else could this be about?"
Sasuke didn't answer, but his arms came around him again, a gentle tremble starting in his limbs that he couldn't control.
"It's for the old woman who always said hi to me when I passed her by," he eventually said, still not meeting Kakashi's eyes. "It's for the men who worked at the police station, who always intimidated me and inspired me at the same time. It's for the girl who wanted to be my sister-in-law one day, for her mother who was made a widow after the kyuubi attack." He swallowed painfully, and looked down at his lap. "It's for the man whose attention and praise I wanted more than anything in the world, who opened up to me about his own misgivings around…just days before he died. Who taught me things, who gave up an important mission just to see my entrance ceremony to the academy, who loved me even though he never said it." He took a break, swallowing thickly, but his voice was louder when he continued. "It's for the woman who was always in my corner, who spoke frankly about situations I didn't understand. The woman who assured me, who raised me, who did more than love me. The woman who gave birth to me and bathed me and fed me and showed she loved me more than I will ever feel again-"
He couldn't finish, his face twisting on a grimace so painful and open it wrenched Kakashi's heart before he could hide it, turn away from him.
"They're gone," Kakashi said simply, gently. "Nothing you can do will bring them back. They're gone, Sasuke-"
"That doesn't mean they don't matter!" Sasuke snarled, and even though he'd baited an emotional response this still hurt. "They matter! The dead matter! Maybe you can just shunt them off to the side as a bad story but I can't! I won't! They deserve vengeance more than most, and asking me to just abandon my revenge is like asking me to discard their memory, which I will never do!"
"And how will dying avenge them?" Kakashi asked quickly, latching on to the first possible argument that might work.
It was clear it did work a bit, Sasuke subsiding, hiding his face in what could only be called shame.
"They wouldn't want you to die," he whispered. "They loved you, they wouldn't-"
"I can't give them what they want," Sasuke said, his voice deadened in a way that had Kakashi's heart pick up in alarm. "I will never be able to avenge them. I'm just as weak as he'd always said, so if I can't avenge them," Sasuke gasped, and pressed a hand to his heart. "If I can't avenge them then all I want is to be with them again. Even if I'm dead."
Kakashi's teeth were starting to ache, this conversation getting away from him.
"You have people here who love you. People who are alive, who you could have a life with."
"Why should I get that when they couldn't? When I can't even earn the life Itachi spared?" He shook his head, then raised his eyes for the first time to meet Kakashi's. "When he…when it happened he told me to 'cling to my wretched life,'" Sasuke explained, and Kakashi carefully forced himself not to react. "He was right. My life is wretched, and I no longer want to do anything my brother says. I want my clan back. I'm done."
He didn't say anything more than that, just turned away from Kakashi fully and laid down on his bed, going so limp it was like he'd died then and there.
"You're not going to be let out," Kakashi warned, but knew it didn't matter to Sasuke. If anyone could overcome the restrictions placed on him it would be Sasuke. If only he knew that.
Kakashi didn't leave, just watched how Sasuke's chest rose and fall even though he wasn't asleep. He felt creepy, but couldn't look away. He felt like if he did Sasuke would die, and that would be that.
His heart was beating too fast.
"If you die I'll avenge you," Kakashi promised before his tongue could catch up to his brain. "I'll go after your brother myself and kill him for what he did to you. I swear."
Sasuke snorted, and Kakashi's heart leapt, the sound stronger than any other expression he's made since his suicide attempt. "I guess both of us have a death-wish."
"No, I don't want to die," Kakashi explained. "I just- I don't understand you, Sasuke, but if revenge means that much to you then maybe there is something to it. Maybe I should trust you know your own feelings more. Maybe I can help."
Sasuke froze, and he knew he was on the right track. This was the first time he'd considered Kakashi's words.
"You'd be avenging me, though. Not my clan."
"I'll do it for the Uchiha too then."
Sasuke shook his head. "You can't. You didn't know them."
"Then I'll come to know them," Kakashi promised. "I'll look at the census, old mission reports, newspaper clippings. I'll ask around for their living friends, get stories from them. I'll look at old academy graduates. I'll make the effort, Sasuke. I'll put their souls to rest."
Sasuke hesitated, then levered himself up to look Kakashi in the eye, and Kakashi almost gasped in relief. He was unsure, but showing more life and vulnerability than he'd had in weeks. Maybe even hope.
"Why?" Sasuke asked, but his voice wasn't accusing.
"…I want a deal," he explained, thinking Sasuke would respond better to that than any feigned caring for the Uchiha clan after Kakashi had just said to give them up. "Give me three months. I'll go kill Itachi and accomplish your clan's revenge, then you and I can take as long as we want working to restore their legacy and put their memories to rest. Three months. Stay alive for three months."
"And if you fail?" Sasuke asked.
If. After everything there was still a part of Sasuke that trusted him.
"…then you can kill yourself," Kakashi said, as if it weren't shattering his heart. "I won't stop you, and I won't let the village stop you." He swallowed. "Three months."
Sasuke clenched his jaw, looking away from Kakashi to consider, but the mere fact that Kakashi could see the consideration on his face meant he already knew his answer.
"Three months," Sasuke agreed, then went back to bed.
***
He got better after that, was allowed out of his room and to rejoin team seven after being thoroughly vetted by his T&I therapist. Kakashi worried that was too abrupt, that Sasuke would learn a lesson from this and be able to manipulate his way out the next time he was committed, but he was hoping to stop that next time from ever happening in the first place. Tsunade had been enraged when Kakashi had requested leave, the village needing jounin, but he was uncompromising. A bad first impression for their new hokage but Sasuke needed this.
Jiraiya took over his duties as sensei for the time being, and seemed really upset about it considering he'd been a sensei before. He'd wanted to leave the village with Naruto but Naruto wasn't leaving with Sasuke the way he was, so that was that. Even though he was staying behind for Sasuke Naruto still avoided him, and Sasuke didn't engage either. Once again it was up to Sakura to keep their team together, and she was trying her best. Enough that they could train and do D-ranks that were way more important and needed to get done while the village was rebuilding. It was also ideal to keep them together as Jiraiya was more than competent in protecting Sasuke as well as Naruto, keeping away any of Orochimaru's influences and even helping him to control the curse mark using the same techniques he would have used to help Naruto control the kyuubi. It was getting better.
Of course, Kakashi learned all this from letters traded through summons.
He needed to be in peak physical condition to fight Itachi, and Kakashi was training every day as he traveled. He had soldier pills by the pack, as chakra exhaustion was always his greatest weakness, but the act of tracking Itachi wasn't that hard itself. He had Jiraiya's information, a last known location that was fairly fresh, and his tracker dogs. There was also the fact that Itachi wasn't exactly hiding, but it wasn't arrogance if he really was that good.
Kakashi had to be better.
It took only one month to find him, and it was interesting to note that…it was very different seeking revenge on behalf of someone else. It did give him more purpose, and somehow…did bring him closer to something he hadn't realized. He'd thought revenge was ignorant, was somehow shutting yourself off from the rest of the world as you pursued an insular personal interest but…he wasn't the one to shunt Sasuke's justice away from the rest of the world, nor the Uchiha's interests. There would be no justice for them if Kakashi didn't do it himself, and that realization…made him uncomfortable. Itachi had been a missing nin for years, and yes he was strong, but they had plenty of strong shinobi who could have gone after him, Kakashi included (previous defeats notwithstanding). There was no reason for Itachi to run wild, especially with how easy it was to find him. Sure, it was hard to find someone who wanted to challenge him with a reputation as large as killing a clan of the elite, but the hokage should have forced the issue. He'd slaughtered hundreds of Konoha citizens and was allowed to just…walk away.
He discovered some of that rage that he saw in Sasuke's eyes, appreciated it for being based on a sound foundation instead of just mindlessness. Rage itself, the revenge alone felt…like justice, like righting a wrong. There were many points in his shinobi career where he was forced to do horrendous things for little reward, and when he started to compare those situations to the purpose he felt now at tracking down a man who'd committed a genocide he…
He still believed revenge wasn't the ultimate point of justice, and he still believed that killing Itachi wouldn't settle Sasuke's soul, but if it would give him the chance to live and try for himself to find peace then yes, Kakashi could see the purpose of it.
He found more than just purpose when he finally tracked down Itachi to a cave on the border of Ame, when he finally looked into the eyes of the man who'd driven his student to believe life wasn't worth it. The man who'd tortured him. A child. At seven years old, and then again at thirteen.
Oh.
Kakashi's wrath had always been a cold thing, something swift and brutal, a flash of lighting and then his fist through an enemy's chest. He'd never felt it bubble up like molten heat, a rage that threatened to shake his limbs and crack his teeth, but he'd also never let himself get this invested before. He didn't know if it was a good thing or a bad thing, but what he did know was that it made him lose the element of surprise because he wanted answers goddamnit. He wanted Itachi to know Kakashi was doing this for Sasuke, for the kid he'd hurt.
"Do you have any idea what you've done to him?" Kakashi asked, grateful his voice came out cold instead of heated, unwilling to let Itachi see how his presence affected him. "How you've ruined him?"
Itachi didn't react to his words, just eyed Kakashi blankly, in a way his rage chose to interpret as contemptuously.
"Go home, Kakashi. I have no business with you."
Good. He didn't want to fight him. That would make the fight sweeter.
"I can't go home," Kakashi said simply. "I made a promise to your kid brother that I'd kill you."
Itachi pursed his lips, and the mere fact he reacted at all mattered, threw him a bit.
"Sasuke sent you after me?" he asked, before humming. "I don't believe it. Sasuke's always wanted to kill me himself."
"Mah, it's true," Kakashi drawled, and it was only because he knew his opponent that he didn't sink hands into his pockets and disrespectfully lean away. "We made a deal."
"…you made a deal."
He didn't really know what to say and what not to say, but it was clear Itachi had a lot of interest in his brother still, or rather, his brother's future challenge to him. Kakashi felt a sense of satisfaction, loving the idea of robbing Itachi of his plans, of taking the opportunity away from him of ever hurting his family ever again, and finally understood why people threw their life into this. It did feel good.
"You know he tried to kill himself," Kakashi said idly. "Tried to throw himself on his teammate's jutsu, so you can imagine how angry I am at the one who hurt him. Really excellent planning there if your goal was to make him stronger."
The sheer gratification of watching Itachi open his mouth and have nothing to say felt greater than any kill.
"You're lying," he eventually settled on. "Sasuke wouldn't do that."
"He had to be committed," Kakashi said simply. He didn't know if it was right to be sharing this, but fed off of Itachi's reactions, believed this would be the thing to hurt him most. "The deal was that he let me kill you. If I fail then I help him escape from the hospital and let him kill himself."
It would take away whatever future Itachi imagined for himself, no matter what happened. He'd either die here or have no possibility of ever bringing to fruition the battle he'd planned between him and his brother. His ambition, at least this one, was never going to happen.
"Sasuke wouldn't-"
"He did," Kakashi snarled. "He's done. He's not looking for revenge anymore, has written it off as impossible. He just wants to die. You've absolutely destroyed him." He grinned mockingly, his one eye squinting to let Itachi see. "Congratulations on being the worst big brother in the world."
Itachi's hand twitched, and it was enough to have Kakashi tensing, scanning the area in preparation for the fight ahead. He'd cornered him in this cave, it not being very deep yet wide enough for jutsu. He couldn't let him escape from this cave into the forest. Kakashi was fast, but he knew Itachi was faster, knew the terrain better. Their fight had to be here.
But Itachi didn't want a fight.
"Sasuke wouldn't-" Itachi choked, then shook his head as he tried to gain composure. "Sasuke wants to avenge the clan. He wouldn't just abandon them."
"He hasn't," Kakashi said dully. "As it's been explained to me he simply doesn't believe he will ever grow to avenge them, thinks that's the reality. So he wants to join them in death, thinks to die would be kinder than to live." He paused. "He said something about having a 'wretched life' that he no longer wanted to cling to. I assume I have you to thank for that."
Kakashi physically jumped at Itachi's reaction to that. He'd started trembling, small shivers in his hand making him clench them into fists, but when he looked up Itachi didn't look angry.
"You can't let him kill himself," Itachi ordered, but his voice was changed, no longer the bland disinterest Kakashi was used to.
"Oh?" he drawled. "Wasn't his death the point, though? You raise him up as a challenge and then cut him down. A sheep for slaughter." He paused. "Maybe he's right. Maybe his life is pointless. Another accomplishment to lay at your feet."
"Stop."
Itachi had yelled it, his shoulders climbing even more, shaking in time to his trembling fists.
That…was not right.
"You can't let him kill himself," Itachi said again, his voice weaker. "You can't."
"Then I guess you're dying here, eh Itachi?" Kakashi asked, but his own voice lacked conviction, his mind whirring. "Of course, since this is your last day on earth, then you might as well come clean to whatever it is you're holding back."
Itachi's breath was just a bit elevated, a bit frantic.
"Okay," he agreed, and once again Kakashi was floored. "If killing me is the only way to protect Sasuke then let's do it."
Kakashi…didn't know what to say. He somehow trusted it, trusted that he was being genuine due to the sheer uncharacteristic attitude of the normally stoic man, but also didn't trust it. It was too spectacular, too different to everything he'd done up until that point.
"But if we do this," Itachi stipulated, and Kakashi carefully did not meet his eyes, would not let his shock pull him into his jutsu, "then you need to protect Sasuke. Don't let him kill himself, and don't let anyone else kill him."
"…interesting conditions."
Itachi huffed, frustrated. "There are…people inside Konoha who might hurt him, people who are only holding off because of me, because of information I have over them."
Kakashi took a breath, and carefully ignored the spike of fear he felt at that information. His team was being guarded by a legendary sanin. They were fine.
"You know the only way to assure they won't do anything is to tell me that information," Kakashi intoned, his voice going away from that mocking taunt into something more business-like.
"I-" Itachi exhaled roughly, inspecting him. Whatever he was looking for he found it very quick.
"Okay," he acknowledged. "Okay."
He lunged, and it was only because he knew what a conniving bastard Itachi was that Kakashi hadn't dropped his guard, was able to engage Itachi in combat without hesitation. He was right to keep the fighting in close quarters, kept up with Itachi's blows, but Itachi was Itachi, and it was a bitch of a fight. He didn't give Kakashi a reprieve, didn't let up for a second to use ninjutsu. It was all taijutsu and blades, all strikes and dodges and avoiding Itachi's eyes like his life depended on it, but after a while his intent became clear. He wasn't trying to win, was taking hits that he shouldn't, but kept pushing forward anyways. He never turned away from Kakashi once.
Kakashi growled, his sharingan keeping up, but he knew he would be the first to falter. Itachi was younger, was pushing Kakashi's more abused body to its physical limits, and all so Kakashi would meet his eyes. There was a moment where Itachi had the upper hand, could have killed him, but he didn't. Fuck.
"Fine," Kakashi growled, and let his eyes meet Itachi's.
He shouldn't have.
He vomited the second he exited the illusion, falling to the ground even though the genjutsu hadn't physically affected him.
"You would never betray Konoha, Kakashi," Itachi explained. "I know this of you, you're not the type, and you know what would happen to Konoha if this got out."
I'm not the type for revenge either. It was amazing how easily people could change.
Kakashi looked up, met Itachi's eyes with a new depth of revulsion. Some people. Some people changed. Other's made cruel decision after cruel decision and dug their heels in as they suffered for it.
The old woman who always said hi. The men who intimidated and inspired. The girl who wanted to marry Itachi and her mother who'd lost her husband. Their father. Their mother.
Kakashi shook his head, couldn't believe that the betrayal of the Uchiha could be worse than presented, but it was. They hadn't just been betrayed by this- this fucking child, but by their village. Civilians, children, those completely ignorant and uninterested to the Uchiha clan's plans for a coup, all slaughtered. Even the ones who'd planned their coup didn't deserve this sort of fate, didn't deserve to be just a bad memory for the biggest traitor Kakashi had ever met.
Worse, was how Itachi thought he was still loyal. As if the version of Konoha he served was in any way shape or form what their home was meant to be.
"I'm not going to kill you," Kakashi decided abruptly, the words coming from a new place inside him, a fresh place of wrath. "You want it. You wanted to use Sasuke for your suicide."
Sasuke had done the same thing, had infinitely more compassionate reasons than Itachi, and still Kakashi was angry at him for what that would have done to Naruto. Facing off against the exact same scenario but with a person who had caused their own hurt, had tortured a child into this path, well, Kakashi had no chance at all of holding back his new wrath. It was as if Rin had conspired from the moment of her meeting Kakashi to die on his hand because she was somehow responsible for all of Kakashi's pain and wanted to simulate justice. It wasn't justice, it was a madman making his brother dance for his own flawed perception of symmetry, of completing the manufactured story where Sasuke was the hero with no regard to what that meant in reality. Sasuke didn't want to be a hero, he just wanted his people to get justice. He just wanted to be at peace.
Itachi wanted that too, but as long as Kakashi lived he would never get it.
"But Sasuke-"
"We're going to lie to him, obviously," Kakashi snarled. "You should be used to that."
Itachi pursed his lips, and Kakashi relished how this hurt him.
"He'll want proof."
"Yup," Kakashi quipped. "Normally I'd take back your head, but I'm thinking Sasuke will be happy with just your eyes."
"Kakashi-"
"The mangekyou is like a fingerprint, unique to the holder," he spat. "Sasuke is well-acquainted with what yours looks like, and he will accept that as proof of your death."
Itachi swallowed. "You want to take my sharingan."
"I want to take your eyes," he corrected. "I want to leave you the blind fool you've always been. You're an excellent shinobi, Itachi. Taking your eyes wouldn't severely impact you."
Itachi shook his head, a rueful smile spreading across his face. "You think I believe that, Kakashi? You want to humiliate me." He looked back into Kakashi's eyes, meeting him with sincerity. "I'm glad that Sasuke has people who care about him this much."
"I don't give a goddamn about how glad you are."
"Ah."
It wasn't enough. The outrage coursing through Kakashi screamed at him that it wasn't enough. He'd come here to avenge Sasuke, but he was also supposed to avenge the Uchiha. Itachi needed to pay, or else the new agitated, enraged feelings inside him would never find rest.
(He had no idea how Sasuke could stand it.)
"Before we do this," Kakashi drawled. "I have a little bit of information to share of my own."
Itachi's eyes darkened, braced for more grim news, but it was Kakashi's turn to use genjutsu on him. Itachi had no reason to distrust him now, and when Kakashi revealed his sharingan met it without fear.
Fool.
It wasn't the tsukuyomi, so he kept what he showed him brief and to the point. Sasuke in the coma he'd put him in, his arm broken and in a gaudy cast. Sasuke awake and enraged, turning on his friends and alienating his loved ones. Sasuke up on that roof, facing off against his friend who didn't want to fight like this, who clearly cared about him and was worried. Sasuke making the decision to die, his eyes closing off as he fell into the rasengan, his expression limp in both sadness and relief. The conversation afterwards, how Sasuke was submissive and without fight. The hospital again, under new a new context, Sasuke put up in a bed without edges he could skewer himself on. The therapy, the effect on his friends, and finally the brutal conversation he'd had with Kakashi where he made his deal.
He showed him all of it, showed Sasuke's pain in a way that was tempered and measured. Considered. This wasn't the screaming rage and pain, the version of Sasuke's suffering that Itachi always saw. This was the aftermath, how he lived in between the suffering, the parts Itachi never dealt with. This was his life, all that was left of it. Because of him.
The hardest part, the part that grated on Kakashi even as he tortured him, was how Sasuke was right. It really was a pathetic life, and the new context around the massacre made it even worse. Sasuke was right. No matter what he did, he would only ever be a victim.
Itachi was on his knees when Kakashi was done, holding his stomach with his eyes wide and devastated and flared red at the pain.
Good.
His mangekyou was out, and Kakashi didn't give him a single moment of warning before he was on him, grasping Itachi's hair to steady his head while his other hand ripped out his left eye. Itachi didn't blink, didn't struggle, but his cheek flinched when the eyeball finally ripped free.
"That's one," Kakashi said, but he wasn't being cruel anymore. He didn't put much stock into physical torture, thought it was a bit crude and unnecessary, so he didn't waste time.
"Two."
He put the body parts in his pack, put them in a scroll so they wouldn't dry out or get damaged on the way back home.
Home. Konoha. The place that had caused all this.
Fuck.
"Don't you dare kill yourself," Kakashi ordered as his last parting gift. "You don't deserve it."
The sentiment wasn't a kindness, and Itachi didn't take it as one.
***
Kakashi threw himself off a few mountains to make it believable, came home covered in bandages and a broken nose, but also came home with a pair of sharingan eyes. Not that the village needed any more.
He didn't go to the hospital, and didn't debrief with the hokage. It was the morning so his team was either at the training ground or had the day off, and he was banking on the former. He was right, and couldn't stop the wrench in his gut as he saw Sasuke train, looking away to try to control his nausea. He was fine, wouldn't be subject to someone else's machinations ever again after this. He'd make sure of it.
"Kakashi-sensei!"
Naruto noticed him first, ran to him as Kakashi limped out of the trees and to his team. Jiraiya and Sakura eyed him cautiously, as all of them knew what he'd been away for. None of them could have possibly conceived how it had ended up.
He put a hand on Naruto to assure him he was fine, but only had eyes for Sasuke who was the stiffest among them, angled away from Kakashi like he didn't care even though he couldn't look away.
"You lost," he declared, and his eyes closed off, fell away from that aching hope to bleak resignation.
Instead of answering Kakashi knelt in front of him and shrugged off his pack. He pulled out the storage scroll with ceremony, unfurling it on the ground flat, and let Itachi's eyes appear in the seals.
"It's over, Sasuke," he hushed, in deference to how Sasuke fell to his own knees, looking at his brother's eyes with complete disbelief blended with painful grief. "It's done."
No one spoke as Sasuke took-in his brother's eyes, no one moved. He reached out and touched, rolled the closest eyeball until the pattern of his brother's mangekyou faced him, then flinched back. He dropped his hands away from the body part, wrapped his arms around his stomach in a way Kakashi had learned was for comfort, for self-soothing. It was a big moment, an undermining of his entire life's goal even though Sasuke himself had given it up, and he let him take his time processing.
But then Sasuke doubled over, and sobbed.
It was so startling, so unusual, that Kakashi didn't react at first. He'd never cried before, not even when he'd tried to kill himself or in his depression afterwards. None of them had ever seen him cry, but these were more than tears. This was a wail, a cry from the deepest pit of himself, somewhere not even Kakashi had seen in all his desperate attempts to understand him in the past weeks. He reached out again for his brother's eyes, but didn't touch. Instead his fingers trailed around the shape of them, almost like a caress, and the gesture made Kakashi stiffen.
"…nii-san…"
It wasn't spoken, just a shaky exhale as Sasuke took breaks between sobs. None of his teammates had heard him, had seen his lips form the word, but Kakashi had.
He'd discovered such new depths to himself on this quest for revenge, new appreciation for what Sasuke had suffered through. He'd discovered new wrath, had felt a new type of rage, but even though Itachi had disgusted him he hadn't hated him, hadn't had enough of a personal tether to Itachi to truly say that was what he felt. He was pitiful, pathetic, and cruel for no reason, but he'd unfortunately never acted with sadism. He'd felt rage and contempt but it hadn't tipped all the way over into hatred.
Now it did, because Sasuke still loved him. Itachi had done all of that, had crafted such a personal hell for someone who still, despite everything, loved him.
Sasuke kept crying, let all of his pain out in front of all of his friends, friends who were shocked and distressed and didn't know what to do. Kakashi normally would be one of them, unable to understand, but now he was the only one who did. He gently got up and kept a wide berth around Itachi's eyes, knew to respect the sharingan in front of Sasuke, and once again dropped to his knees next to his student. Before, he couldn't imagine doing this, believed Sasuke would take it as a condescension and resent him, but now Kakashi knew better. He'd had this, had comfort and warmth in his life before the massacre despite his clan's reputation. He knew how to be comforted, and he desperately needed it.
Kakashi reached out and drew Sasuke into his arms, ignoring his own flare of discomfort. Kakashi himself didn't chase physical comfort, didn't seek out this sort of relationship with his students, but it wasn't like Sasuke had anyone else. He held him, brought his face to Kakashi's chest while his arms went around his shoulders. It reminded him of how he'd had to restrain him that day on top of the hospital, worried Sasuke would hurt himself if given the chance. The sentiment behind this gesture wasn't that different, but instead of the limp submission he was met with even louder cries, Sasuke's hands clawing into Kakashi's sleeve and holding him there.
He dug his face into Kakashi's vest, and Kakashi knew he'd made the right decision.