After hearing Leo's account, Yukino finally confirmed it. Someone had gotten ahead of her again.
Bad enough that Asuna had beaten her to being "favored" by their scumbag master. Now even Utaha had reached the domain of Balance Breaker before her. Yukino didn't know what to feel.
"Stop comparing yourself to others in areas that aren't your strength." Leo read her expression instantly. "Your real talent has always been demonic power. And in that department, didn't you break through faster than anyone?"
That calmed her down somewhat.
It was true. Her demonic power was the first to break through in the entire Eligos peerage. Even Ram and Ravel fell short of her in that regard. She was second only to Leo himself in raw magical ability.
That was her real domain. There was no point measuring herself against others where she was weakest.
Besides, even when it came to Balance Breaker, she wasn't necessarily behind Utaha.
"Kasumigaoka-senpai may have touched this domain before me, but I think I've overtaken her. I completed it faster than she did."
As she spoke, Yukino glanced toward the Ice Princess at the bedside. Demonic power flowed from her body through invisible channels into the Sacred Gear, and a formless wave of energy rippled across its surface.
That wave was powerful enough to affect the flow of the entire world around it. The Ice Princess's aura surged visibly, climbing at a speed the naked eye could track.
Seeing this, how could Leo not understand?
"You've already completed Balance Breaker?"
He was genuinely surprised.
Yukino nodded. Her usually cold expression softened noticeably, her improved mood plain to see.
In truth, she hadn't expected it either. Just last night she'd been agonizing over how to push her Sacred Gear through that final step and truly achieve Balance Breaker. Then she woke up this morning and found it was simply... done.
Why?
After her initial confusion, Yukino understood immediately.
Leo figured it out just as fast.
"Well, well. The great Yukinoshita Yukino finally got eaten up by the kind of man she's always looked down on. How could there not be some intense emotional upheaval?"
Leo's teasing made Yukino's cheeks flush. She glared daggers at him.
But she didn't deny it.
Last night, her emotions had been... extreme, to say the least.
How could they not be? First she'd discovered someone had beaten her to the punch. She was Leo's first peerage member, and yet Asuna had gotten there first. She'd been left standing outside the bathroom, listening to the absurdly dramatic sounds from inside, her heart in turmoil. Then a certain scumbag master had grabbed her, tossed her onto the bed, and taken her on the spot. And then he'd dragged out the girl who'd been eavesdropping at the bathroom door for one massive shared bed. How was someone who'd been completely inexperienced until that very night supposed to handle all of that calmly?
Last night was, without question, the most mortifying experience of Yukino's entire life. More shocking than discovering she lived in a world full of supernatural powers. More shocking than learning she'd been killed and reincarnated as a devil.
Even now, just thinking about it made her want to dig a hole and bury herself. Her heart still couldn't settle, let alone during the actual events themselves.
So Yukino was certain: somewhere amid last night's violent emotional storm, she'd unknowingly completed the final step of her Sacred Gear's Balance Breaker and crossed into that ultimate domain.
"Should I be congratulating you, then?"
Once Leo pieced together what had happened, he burst out laughing.
Sure, it sounded absurd. Achieving Balance Breaker through that. Ridiculous on every level.
But when you compared it to Hyoudou Issei from the original story, it suddenly didn't seem so outlandish.
After all, that guy had reached Balance Breaker by poking breasts. If Yukino could reach it through a more... crowd-pleasing method, why the hell not?
Never mind whether it was absurd. The only question that mattered was whether it had caused an intense enough mental shift to satisfy the conditions for Balance Breaker.
As long as the Sacred Gear received a powerful enough emotional shock, that shock became the catalyst for reaching the Balance Breaker domain.
How exactly that shock came about? Irrelevant.
What mattered was that Yukino was now the second person after Leo himself to reach Balance Breaker. That was enough.
"This is only the beginning." Yukino ignored his teasing, or rather, realized that reacting would only make him more insufferable, and said coolly, "I've reached Balance Breaker, yes. But I still need time to get it under control."
"Fair enough." Leo was a Balance Breaker user himself and understood what she meant. He nodded. "You should be able to communicate with Ice Princess now. Has she told you how long you can maintain Balance Breaker at your current level?"
Yukino closed her eyes and reached out to Ice Princess.
A moment later, she had her answer.
"At my current levels of demonic power and stamina, I can maintain Balance Breaker in combat for roughly three hours."
Yukino thought that was pretty respectable. She'd asked Yuuto Kiba about this before. He'd told her that after activating his Balance Breaker, he could fight for about one hour.
Compared to Kiba, three hours was solid.
Leo, however, frowned.
"Not good enough. Three hours is far too short. You need to maintain Balance Breaker for at least three days before I'd call it passable."
Yukino blinked. "Does it really need to be that long?"
She wasn't entirely convinced. Three hours was enough to settle most fights.
But Leo pressed the point. "Think about it. What if something like the Old Satan Faction attack happens again? What if you get teleported into some labyrinth dimension where you have to fight through room after room before reaching the final boss? Would three hours actually be enough?"
That shut her up.
If she were trapped in that kind of situation again, three hours would be nowhere near enough. Even if she could fight through the earlier stages and reach the final chamber, she'd have almost nothing left to defeat whoever was waiting there.
And that was just maintaining Balance Breaker passively. If she used her Sacred Gear's abilities on top of that, the additional drain on her demonic power and stamina would cut her time down even further.
Three hours really wasn't going to cut it.
In the original story, Issei could only maintain Balance Breaker for thirty minutes when he first achieved it. If he used Boost, that dropped to about fifteen minutes, forcing him to carefully ration his stamina in every early fight. Yukino wasn't quite as bad off as Issei, but she couldn't afford to be complacent either.
"For reference, the current White Dragon Emperor can maintain Balance Breaker for a full month. And even he nearly exhausted himself in our fight because he used his abilities too many times."
That hit home hard.
Leo had already briefed the peerage about the current White Dragon Emperor, so Yukino knew the details of that fierce battle outside Kuoh Town. If even Vali, who could sustain Balance Breaker for an entire month, had nearly run himself dry from overusing his abilities, then it was obvious: when facing a powerful enemy, both demonic power and stamina would drain at a brutal rate. Nobody could afford to hold back.
In a fight where you had to go all out, what mattered was how long you could last while burning through everything.
Yukino did a rough calculation. If she went all out, Balance Breaker active and abilities firing freely, she probably couldn't even last thirty minutes.
That was definitely a problem.
"What about you?" She turned to Leo. "How long can you maintain your Balance Breaker?"
"Me?" Leo raised an eyebrow. "Conservative estimate, about three months."
Yukino fell silent.
Three months.
That dwarfed her three hours. It dwarfed Vali's one month by a massive margin.
But it made sense. Leo was now a ten-wing special-class devil, a full tier above Vali's eight-wing class. Even though Vali was a descendant of Lucifer with naturally immense demonic power, enough to briefly invoke Juggernaut Drive by burning massive amounts of energy, Leo was a Perfect Devil. His bloodline was in no way inferior to Vali's, and was quite possibly superior.
Three months was genuinely a conservative estimate. Leo could probably sustain it even longer, but just as Vali had to account for the cost of using his abilities, Leo factored in his own ability usage and settled on three months as a safe figure.
"You already have High-Class Devil levels of demonic power. Most of the cost of maintaining Balance Breaker gets offset by magic. If you can improve your physical stamina on top of that, you should be able to hold it significantly longer."
Issei was the opposite case, born with demonic power so weak it didn't even match a Low-Class Devil's. His only option was physical training, using raw stamina as fuel for his Sacred Gear. Yukino's situation was the mirror image: she relied on demonic power as her fuel.
If Issei's magic had been even slightly stronger, his Balance Breaker uptime would've improved dramatically. Unfortunately, he had zero talent in that area and had no choice but to grind out physical training.
And Yukino was in a similar boat, just flipped around.
"My stamina has always been my weak point. Even becoming a devil didn't really fix that."
She was genuinely frustrated. Back when she was human, Yukino's stamina had been terrible. She excelled at practically every sport, tennis, horseback riding, you name it, but her endurance was so poor she could never keep it up. Before stepping onto the field and after were like two completely different people.
Before: the most dazzling star on the court, untouchable in skill.
After: said star usually lasted a few minutes before running on fumes.
Reincarnating as a devil hadn't changed this much. Her constitution was far stronger now, and her stamina certainly exceeded a normal human's, but compared to other devils she was noticeably behind.
How far behind? Dead last in the entire Eligos peerage.
Forget Asuna, who was a close-combat specialist. Even compared to Utaha, a literary girl by any measure, Yukino's stamina fell short. As for Mahiru, she'd actually been one of the top athletes in her class before becoming a devil. Ram and Rem went without saying — they were Oni, born with powerful bodies. Even Ram, whose talents were lopsided, had better endurance than Yukino. Ravel was about the same, but could at least outlast her.
Yukino wasn't bad at sports. She just had no stamina. Her endurance was a disaster.
Unlike Leo, who'd seen his physical abilities surge after evolving into a Perfect Devil. He could probably sustain Balance Breaker on stamina alone for ages, without touching his demonic power reserves.
"Do what you can to work on it," Leo said. "And if it really doesn't improve, just specialize entirely in demonic power training. Either way it's all fuel. Stamina or magic, doesn't matter."
Yukino nodded, but privately resolved to put real time into training her endurance.
"It's getting late. I'm going to test my new power."
Decision made, she rose without hesitation, gathered her clothes from the floor, dressed quickly, and left.
"Wait... you're in that much of a hurry?"
Leo stared after her. He'd been hoping to savor the morning a little longer. But a moment later he turned to the other side of the bed, his gaze settling with unmistakable intent on the still-sleeping Asuna.
The chestnut-haired girl jolted awake, eyes wide.
The atmosphere in the room turned intimate once again...