The sunlight is almost blinding when they leave the palace and return to Soul Society, and Erich shields his eyes against the glare, feeling even more exhausted than before as he catches sight of their welcoming party.

Urahara he expected, given the man’s investment in Kurosaki’s wellbeing, and Kyoraku and Ukitake are… not really a surprise, given that he barely prevented Ukitake from sacrificing his life for a useless effort, but the others—

Well, no, Unohana isn’t much of a surprise either; she’s a healer, and given who the three of them went to fight…

It’s the others that Erich is surprised — and angered — by. Specifically the one standing a bit apart from the other Captains, painted skin and ostentatious golden headdress and gleeful, greedy eyes fixed on him — on all three of them — as they walk from the portal.

At his side, Uryuu stiffens. Tucks himself tighter against Erich’s body and tightens his grip, as if simultaneously trying to hide and keep Erich safe.

(“He killed them,” Uryuu had admitted one late night, curled against Erich’s side with his face buried against his chest. “He killed them! Tore them open while they were alive, just to— just to see! Just to know what made a Quincy a Quincy!”)

The stranger stirs in his soul. Uncurls. Reaches out and brushes question-concern-need? against Erich’s mind. Catches the ripple of memory and presses further, gently tugging at memory-threads until—

Determination-fury-resolve surges to the fore as the stranger nudges Erich aside, tucking him away with a casual ease that leaves Erich breathless with terror, and then lifts a hand to his chest, palm in and fingers curling. There’s another strange twist, followed by a sensation almost like claws against the inside of his ribcage, and—

A jagged, blood red pillar erupts beneath Kurotsuchi, spearing up-up-up—

Kurotsuchi doesn’t get a moment to react before the pillar has ripped through his body and out the top of his head. The horrific image remains for a bare heartbeat before the pillar dissolves into glimmering motes, leaving Kurotsuchi’s shattered body to collapse, torn and bloodied and barely recognizable as a person…

In an instant, every Shinigami around them draws their blade.

“Explain yourself,” Kyoraku barks, his lips bloodless and his remaining eye dark with emotion.

The presence hums and glances down at Kurotsuchi’s corpse. “Threats like that… they should be removed before they become worse,” it declares, tone heavy with the weight of knowledge. “There’s no justification for experimentation on unwilling subjects.”

“You aren’t Rerugen-san,” Urahara says with assurance, and the stranger… jolts. Not at being called out, but… at the name?

“I’m not,” the stranger agrees while tugging their arm free of Uryuu’s grip and forcing their exhausted body to stand on its own. Inwardly, the stranger brushes curiosity-question-uncertainty at Erich, focused on Rerugen, and it’s… it’s a weird feeling, a shivery feeling, like… like this might be something precious, something priceless—

“Rerugen is my family name,” Erich answers cautiously, uncertain why it matters, why the stranger might care, but—

The stranger shivers again, wonder-disbelief-sorrow curling through its presence, before it shakes their head and forces itself to focus on the Shinigami around them again.

“What do you want?” Urahara demands as he takes a step forward, sword aimed at Erich’s chest and gaze steady.

The stranger gives a tiny, twisted smile and answers, “To protect those your Rerugen-san cares for.”

“By killing Kurotsuchi-taicho without warning or provocation,” Kyoraku cuts in dryly.

“By killing a known threat who has, with forethought and intent, gone after Rerugen-san’s people,” the stranger corrects sternly. “By killing a threat who was eyeing us with clear intent.”

There’s something like a hum against their skin, a buzz that resolves into a warm-proud-pleased whisper of, “Well done, my Successor,” in their mind, and the stranger straightens a bit in response.

“Io,” the stranger murmurs in relief. “You’re alright.”

Io laughs softly and says, “Of course I am— who else would remind you to watch your footing, after all?”

“That was one time!” the stranger snips back fondly, before refocusing on the threats around them as Io’s cheerful laughter rings through their mind.

Urahara’s eyes narrow and the corners of his lips turn down, gaze intent and a bit… confused?… as he watches Erich warily. “And what will you do now?” he asks as he takes another step forward, his free hand curling slightly in preparation for— something. A kido, Erich suspects, but he could be wrong; Urahara is a tricky foe, always planning multiple steps ahead, and Erich makes sure that the stranger controlling him knows that.

The stranger’s gaze slides from Urahara to Ukitake to Kyoraku and back. “What will you do when I fade?” it asks, carefully relaxing their stance to something less obviously threatening. “Will you strike Rerugen-san down for calling me forth? Will you punish him for my actions?”

Kyoraku grimaces and slowly, reluctantly lowers his blade until it’s no longer pointed at them. “Do you swear not to attack anyone else without provocation?”

Erich can feel the way the stranger prods at him, wondering if Kyoraku’s question is reasonable or if there are any other threats he knows about, and it’s a relief that he can send agreement back: there aren’t any other threats like Kurotsuchi that he knows about. Not that still exist, at least.

“I do,” the stranger says with a shallow nod.

Kyoraku clenches his jaw and glances to the side, having a wordless conversation with Ukitake that ends with both of them cautiously sheathing their blades. “We’ll need to look into your accusations, of course, but we’ll overlook it this time,” Kyoraku says with a shallow, wary nod. “And we won’t do anything to Rerugen-san.”

The stranger stares at Kyoraku for a long moment, then sweeps their gaze over the others before settling on Urahara and asking, “And you?”

“Maa, no trust that I’ll keep to Kyoraku-taicho’s promise?” Urahara asks with fake cheer, letting his sword-point dip towards the ground.

“You still have your sword drawn,” the stranger answers dryly. “I think that’s answer enough.”

Urahara stares at them in consideration, then sheathes his blade and takes a step away, expression shading towards amusement as he asks, “Is that better?”

“I don’t think he’ll hurt me,” Erich tries to reassure; he can feel how exhausted the other is — wherever the other came from, it was not a kind moment in time — and he can also feel the other’s determination to push through, to make sure that its actions have no repercussions for Erich, and it’s— it’s nice. It’s more consideration than he ever expected from a virtual stranger, especially a virtual stranger shoved unceremoniously into an unfamiliar body and asked to immediately fight for their lives.

The stranger meets Urahara’s stare head on, wary-watchful-thoughtful, then slowly nods and says, “It will do,” before abruptly releasing its hold on Erich and slipping back deep-deep-deep into Erich’s soul.

Erich gasps. Stumbles forward. Feels his legs give way once again and closes his eyes in resignation, waiting to hit, waiting for the jarring pain, waiting to be mocked or chided or— or something—!

Strong arms catch him before he can fall far. His head lands on a firm, broad chest. Familiar reiatsu settling like a blanket across his raw senses—

“Back with us, Rerugen-san?” Urahara asks softly as he hauls Erich up against his side, easily supporting his entire weight. “Are you alright?”

“I’m fine,” he mutters in exasperation. “The other… it— he—” he finally corrects himself, not wanting to continue calling another being an it, especially when it’s probably his fault that the unknown is trapped within his soul. “He isn’t a bad sort. Just… protective.”

Urahara scoffs at that descriptor. “Protective, is it? I think he goes a little beyond just protective,” he says as he adjusts his grip on Erich and brings a glowing hand up to Erich’s chest, sinking a healing kido deep into Erich’s body. “This— Rerugen-san—” Urahara hesitates, grimaces, then continues with— “I’d prefer if you stayed at the shoten, given what I sense.”

Uryuu’s head comes up at Urahara’s words, attention pulled away from where Unohana is treating Kurosaki. “What’s wrong?”

Erich swats at Urahara’s hand, even if the threads of healing do feel nice as they soothe away the aches of straining against Yhwach’s control. “I’m just exhausted,” he hisses in exasperation. “I can take care of myself just fine at my own home.” When Uryuu just gives him a doubtful look, Erich fixes him with a stern look and says, “I ache and I need to not use my powers for a while, but I don’t need anything but rest,” then switches his look onto Kisuke and adds, “And I especially don’t need anyone hovering.”

“It’s not hovering if it’s necessary,” Urahara mutters barely loud enough for Erich to catch, then clicks his tongue and lets his kido fade. “Maa, if you’re certain, then I suppose I’ll let it be,” Urahara announces brightly, before crouching down and sweeping Erich up into his arms.

“Urahara-san!” Erich barks, ignoring the way his voice goes a touch higher than usual in shock. He latches onto Urahara’s jinbei and glares at the man as he demands, “Put me down this instant!”

“Mmmmm… no!” Urahara flashes him a cheeky mask of a grin and adjusts his grip, saying, “Rerugen-san has already admitted to being exhausted, so Rerugen-san should take this time to rest!”

Erich starts to snarl a response, then freezes as he feels Urahara’s reiatsu sinking back into his body, but this time— this time it isn’t healing kido, but rather— rather—

Erich covers a yawn. Struggles against the growing weight in his limbs, the fog in his mind, the sense of calm-safety-warmth radiating from Urahara’s kido—

“Bastard,” he hisses as his head thumps against Urahara’s shoulder and his eyes slide closed. “You can’t just—” another yawn cuts him off— “can’t just put me to sleep like s-some recalcitrant child…”

Urahara hums and softly asks, “Who said anything about making you sleep? I’m just helping you relax, Rerugen-san. Whatever your body decides to do with that is hardly my fault!”

“Semantics,” Erich growls into Urahara’s chest, unable to muster the energy to lift his head back up.

“Go to sleep, Rerugen-san,” Urahara says as he gently tucks Erich more firmly against his chest. “I won’t let anything happen to you or the teens.”

Erich grumbles a wordless protest but stops trying to fight. There’s no point, anyway, not with how tired-exhausted-wrung out he is.

He breathes a sigh. Tucks his chin into his chest.

And sleeps.