The reverse summoning faded, leaving behind the wet silence of Shikkotsu. The ground gave slightly under his boots, soft and warm like something alive.
The mist pressed close, carrying that faint acid sting that burned the throat if he breathed too deeply.
Ryusei took one step forward.
The pulse beneath the surface followed, slow and steady, like a creature's heartbeat measuring his rhythm.
"Back again," he murmured quietly, almost to the ground itself. "Guess it's my turn now."
He hadn't come to admire the view.
Three months had passed since his last visit here with Nagato.
Now Ryusei had returned alone, ready to face the black pools himself.
His body was finally prepared, refined through additional months of conditioning and vibration training, and the insights he'd gained from watching Nagato's attempt had given him everything he needed to try and survive it on his own.
Long enough to prepare to stop being a spectator.
He wasn't here to watch anyone else dissolve this time and get those awesome powers.
He closed his eyes, letting his chakra spread outward.
He exhaled, closing his eyes for a brief moment. "Alright, Katsuyu," he said softly. "You were right in the past. I wasn't ready. But now…"
The air shifted.
From deep beneath the surface, something vast stirred.
A tremor rolled outward through the terrain, steady, slow, and deliberate.
The mist thickened as pale blue light rose from the ground, and the enormous, mountain-like shape of Katsuyu emerged once more from the depths.
Her translucent body glistened under the faint green light, a creature of patience and endless memory.
One of her immense eyes rolled toward him, unblinking.
"Ryusei… again? Do you humans ever rest?"
Ryusei's gaze, however, just lingered on her for longer than usual before responding.
It wasn't his first time seeing Katsuyu's true form, so the sight no longer unsettled him, but he still remembered that first encounter vividly, the moment he realized how far beneath her he truly was.
That power wasn't chakra; it was the weight of nature itself, a living mountain of pure natural energy he couldn't even begin to challenge back then. It had humbled him more than he liked to admit.
Still, knowing what he knew now, he couldn't help the faint smile tugging at his lips.
For all her enormity and ancient strength, Katsuyu was just an old "shut-in" with a hard shell and a soft core.
That was why he always dared to tease her, even when standing before her real form.
But behind the jokes, there was genuine respect.
She represented a level of existence he still hadn't reached, one he was determined to.
Watching her made him think again about this world's hierarchy of beings, those ancient creatures like the toads and serpents that had been part of it since the beginning.
Especially that massive ancient toad lurking behind Hagoromo's myths, called Gamamaru.
They were nature's originals, chosen by the planet itself.
He was just an intruder trying to steal a seat at their table.
Katsuyu's massive eye, meanwhile, shifted slightly, the movement slow and deliberate.
Her voice rolled through the mist, patient and dry. "Ryusei," she said, tone edged with faint amusement. "If you keep staring like that, I'll start to think you've finally accepted dying. I'd rather not see you prove it."
He smiled faintly, as if caught. "Just wondering if you've gotten any bigger since last time."
Her low rumble passed through the ground. "Flattery won't save you when the forest starts digesting you again."
Then her tone deepened, the humor flattening into that familiar ancient weight. "I was beginning to wonder when you'd crawl back here to unwisely dissolve."
Ryusei smirked lightly, lifting his chin. "I prefer the word 'evolve.' But yes, I'm back. You said this place doesn't teach, it remakes. So let's see what kind of monster I become this time."
The forest's pulse deepened again, slow and rhythmic, as if laughing quietly in response.
Katsuyu's tone carried faint amusement. "Bold as ever. But confidence doesn't stop the forest from eating."
"I know," Ryusei said, stepping closer toward the center. "That's the point."
"Then at least try to taste better than the last one."
They began walking together through the mist, the ground pulsing faintly beneath their steps.
Acidic droplets hissed softly around them, and the glow of the bone-white pillars followed their movement like dim, living eyes.
After a while, Ryusei spoke in his usual offhand way. "You know, I've always wondered, why are you so much nicer to Tsunade than to me?"
Katsuyu's voice came slow and dry. "Because Tsunade only summoned me when she was dying. You, on the other hand, treat me like a spare limb you can't stop waving around."
He smirked faintly. "Come on, I've improved your lifestyle. Broader fieldwork, constant exercise, better chakra circulation—"
"Overuse is not improvement," she cut in flatly. "You've called me more in one year than Tsunade did in her entire lifetime. At this point, half my fragments flinch when they hear your name."
Ryusei chuckled quietly. "Then you should be proud. You've never been this productive in centuries."
Her rumbling exhale rolled through the ground. "Proud isn't the word. Tired, maybe. Though I suppose it's an achievement to exhaust a creature built for regeneration."
He gave a faint grin. "You love it."
"I tolerate it," she corrected. "And you. For reasons that still escape me."
The mist thickened again around them, glowing faintly as they neared the inner basin.
Ryusei's smirk widened. "Admit it, you'd miss me if I dissolved."
Katsuyu's massive eye tilted toward him, the faintest pulse of light moving behind it.
"If you dissolve, I'm keeping your bones as a reminder not to contract with ambitious humans again."
He laughed softly, and the forest seemed to breathe with them.
Katsuyu moved in silence, her thoughts lingering on the human walking beside her, the one who was about to wager his life against her forest.
Tsunade's bond had allowed Ryusei to form the contract with her in the first place, but he'd twisted that privilege into something entirely new.
He never treated her like a myth or a weapon like other shinobi in the past, more like a living system he intended to dissect, understand, and constantly rebuild.
Always experimenting, always forcing her biology and summoning network into new shapes, as if she were some sprawling machine he hadn't finished assembling.
She met his relentless creativity with her usual blend of irritation and, later, reluctant respect.
A small part of her, though she'd never admit it aloud, was curious, almost eager, to see what he would build from the gift she could give him, once the forest and its Sage power became his to reshape.
In the beginning, it was probably Tsunade's name and favor that bound her to him, or maybe it was just simpler to go along with his chaos than waste the effort resisting it.
However, with time, their dynamic had changed anyway.
The orders turned into conversations, the complaints into routine.
She still scolded him for overreach, still muttered about his insanity, but there was quiet fondness buried beneath it, a concern she never voiced yet knew he always caught.
Ryusei called her, with his usual smirk, "the most powerful recluse in the world" and "the most oversized shut-in."
Katsuyu, never missing a beat, occasionally called him "the most exhausting human since life began."
But he wasn't entirely wrong. She was lonely, though she'd never say it out loud, and faintly amused that Ryusei was the only human who ever chose to tease her instead of revere her.
As they moved deeper, Ryusei's eyes wandered, quietly taking it all in.
The Shikkotsu Forest wasn't just full of natural energy; it was even more unique than that.
It has absorbed so many failed Sage trainees over time that it has learned from them.
Every failure strengthened the forest itself, its natural energy, its corrosive environment, its awareness.
So, anyone who came afterward faced an even harsher, more adaptive environment.
It was built on everything that had come before, on the hopeful people who failed here.
Every patch of ground, every drop of mist had swallowed centuries of forgotten ambition.
It was almost poetic in a sense.
The forest didn't bury its victims; it reused them.
It didn't forget. It evolved.
Over time, that cycle turned the place into something more than alive.
The soil carried half-digested traces of bodies, chakra, DNA, souls, and willpower, all blending together until even the air felt heavy with memory.
Every failure had become part of the system, and now the system resisted everyone who tried again.
Ryusei found the idea almost elegant.
A living archive of dissolution, constantly refining itself through the people it devoured.
If he failed here, he wouldn't be buried either. He'd be studied as well.