Degeneration
No one really believes Kon's that observant and he knows this. But he can't help but notice the difference in Ichigo's body as time goes on. Whenever they switched, in the beginning, it was fine. The body reacted as well as it did the first time Kon had taken it over.
As the days turn into months, however, there is a change. He moves just a bit slower when he's running. His arms shake when he lifts something. His breathing grows labored easier and sometimes his vision spins.
He doesn't know if Ichigo ever notices it, but Kon can tell something is wrong.
One day, Ichigo wakes up and can't breathe.
Panic doesn't set in for a full minute and by that time, Ichigo has managed to sit up, his hands pressed to his throat. It feels like something's blocking his throat, stopping air from entering or leaving and his lungs are burning. He wants to retch but he can't and that's almost scarier than the silver dots obstructing in his vision.
Then it stops and Ichigo gasps, dragging in a large breath as he leans forward. His heart is pounding and his arms shake as he runs his hands through his hair. He's breathing heavily and that's how Rukia finds him when she opens the closet.
"Ichigo?" she asks quietly, eyes as sharp as they always are. Ichigo shakes his head at her, struggling to calm his breathing. It's fine now, the air flowing as easily as it did for years. But it's shaken him and it's worse because he doesn't know why it happened.
"Nightmare," he says shortly, standing and gathering his clothing for the day. Rukia believes him and leaves through the window, sending him a pitying glance. The excuse is believable, what with all the fighting and blood he's encountered over the months. It's only natural that some of that would nestle into his subconscious and manifest in his dreams.
He wishes that was it, but knows it isn't. It's worse.
Soon, he develops a cough. When it starts, his family thinks it's just a cold and tries to help. Cough syrup, soup, they even let him stay home for a day.
It doesn't help. Ichigo pretends it does, holds in coughs until he's on his way to school, tries not to notice how they burn. Water helps, but as the days go by, the cough steadily gets worse until he can barely hide it from his family.
The only reason he can is because he's rarely home for longer than it takes to sleep and eat. The rest of the time, he's out fighting Hollows and doing his Shinigami work and that takes up so much of his life that he doesn't even notice his cough disappears when he leaves his body.
The day he tries to go back into his body and it almost rebels is the day he knows something is horribly wrong.
Ichigo manages to get back into his body easily enough, manages to catch Kon's pill as he coughs, but then he can't stop and he's bent over, coughing until his head hurts and his throat feels torn and drops of blood slip past his fingers. His palm is coated in crimson and his vision is spinning so bad he has to lean against a wall, his limbs shaking.
He doesn't know what brought about this increase in his sickness and, as he stumbles home, hopes it never goes further than it has today. Ichigo doesn't want to be forced under the worrying stares of his family, doesn't want to worry them at all.
So when he gets to his home, he sneaks in the back way, makes his way into his room as quietly as he can and hopes that Yuzu doesn't come to investigate. He's acted odder than this, hasn't he? They don't need to worry.
But Ichigo worries. What's happening to him, what's started that makes changing so difficult, makes his body weaken to the point that he shakes? He doesn't know and Rukia wouldn't be able to help him, not with his still human body. This is a first and no one would know what's happening to him, would they?
When Ichigo goes to sleep that night, a small, traitorous part of his minds prays he wakes up in the morning.
He wonders if it was because of the Menos. That day, Ichigo had released so much power, his reiatsu overflowing and causing his body to lock up. Could that have been the catalyst to this degeneration? Ishida hadn't been able to escape the fight unharmed and even now, Ichigo can see his arm shake.
Ishida hides it well, though, and none of their classmates notice. Ichigo wonders if they would ever notice anything wrong with him. He knows he looks worse these days, just a bit too pale compared to how he was before. Does anyone see it? Shouldn't they?
(Does he want them to?)
"Are you... feeling alright?" Rukia asks in the courtyard after school, her voice oddly hesitant. Ichigo tenses and forces himself to relax after he does.
"Yeah," he says, moving his free arm around and pretending the action doesn't stress the limb as much as it does. "Everything feels fine."
"I see. That's good." Her voice is quiet, oddly musing and Ichigo can't help but feel just a little bit threatened by it. It's irrational and confusing and he doesn't know why he reacts like this. Maybe he wouldn't have last month, before everything seemed to fall out of control.
"Is another one like yesterday coming?" he asks, referring to the Menos, and trying to direct her attention off of him. Rukia scoffs lightly.
"Menos Grande hardly appear that often," Rukia tells him, bowing her head with a smirk. Ichigo sighs faintly in relief and latches onto something else.
"You're," he pauses, wondering how to say it. "You're acting kind of strange today." Because she is; she's never asked him how he felt about everything before, not in this tone. And she's been distant, besides. "Did something happen?"
Rukia doesn't answer right away, staring at her feet and Ichigo feels some sort of tension rile up inside of him. Anxiety, he thinks, but what about?
"Well," she starts, her voice hesitant enough that Ichigo really has to wonder what happened to her. Is something wrong with her, spiritually? Did giving him her powers cause something to start, something similar to how Ichigo's body seems to be degrading as the days go by? Maybe not, if her gigai isn't so much like a real body. But what of her soul? Is the lack of power doing something to her?
He doesn't find out, because she doesn't finish. Kon takes that moment to run up to them, dirty and tearful and Ichigo is secretly, shamefully, glad. He doesn't want what's happening to him to come to light. Not like this, outside the school where anyone could hear. And not to Rukia, who would worry and might even cry, if her current state is anything to go by.
They fix Kon and go home and Rukia never finishes the conversation. Ichigo lets it go, watching quietly as Rukia attempts to act like she did before, brash and sarcastic and superior. It feels false.
The next day, she's gone. And things fall apart even more.
Abarai manages to wound him and Ichigo tries to ignore how sluggishly his blood flows from the wound. Isn't it supposed to be moving faster than that? Shouldn't he be less affected in this form? He doesn't know and wouldn't have wondered before all of this nonsense happened. Before that night when Rukia stumbled into his life and changed it all with a stab through his heart.
(Vaguely, in the part of his mind that's trying to puzzle out when this fading started, he wonders if that was the start. The very day he gained these powers, had stabbing him been too much for his body? If it's been a physical sword, he would have died; maybe it didn't matter. His heart still suffered the same.)
Another slash, this time in his right shoulder. He drops his zanpakuto (unnamed; since when did they have names?) and watches with blank eyes as Abarai raises his sword for another strike. Surely, this will be his last and then what will happen? His soul will be dead; will his body finally quit? Will Kon have it now? Only, he'd left it with Urahara, Kon still in the toy. What happens to a body without a soul, anyway?
He's dazed, thinking like this, feeling the blood run down his arm. Before him, he can hear Rukia yelling, but it's like listening through water.
Rukia.
That's right. Even if he's dying, he has to save her. She's wrecked his life, changed it beyond anything he'd expected, but he can't just let her go. Not like this, not to these people who want her dead for doing her job.
Grimly, he stands, his grip tightening around his retrieved zanpakuto, even though he knows nothing will help him now. At least, if he can injure Abarai, maybe Rukia will be able to get away.
(There's still that other man, standing and watching the fight. Will he step in if Ichigo manages to defeat this redhead?)
The air around him his thick and his body is tingling. It's possible his wound is closing, just a little bit quicker than it otherwise would, but he doesn't really know. All he knows is his reiatsu is gathering, flooding out like the day he'd fought that Menos.
It's like an adrenaline rush. Ichigo's body feels lighter; everything looks like it's moving slower. Abarai can't touch him now and Ichigo plays it up, dodging that stupid sword and getting his own hits in. And the longer he fights, the more he can feel his reiatsu building; heavier and heavier until Abarai can barely move and Ichigo is so high he barely cares that he's grinning like a madman. Is this what it's like to be alive? He hadn't known he missed it so much.
And then it stops. It's so sudden he freezes, his breath catching in his throat as he falters, eyes only on his sword.
Or what was his sword. Now there's nothing more than a nub of metal barely two inches long. There's nothing on the ground, nothing to suggest that his blade just shattered out of nowhere, but that has to be what happened. A sword can't just vanish.
Was it him? The man that just stood back, who watched everything with such a blank face? Ichigo hadn't even seen him move...
Then the pain comes back and he's gasping, dropping to his knees. Blood sprays from the new wound across his chest, a wound brought about by a strike he never saw. How..?
Then it's dark and he wonders fleetingly if it's possible to die twice in one night.
He wakes up in an unfamiliar room. Ichigo is only thankful that he manages to wake up at all.
He feels weaker than ever and knows he must be back in his human body. It's such a difference from his spirit form, even after being sliced up so neatly. It's almost funny and the only reason he doesn't laugh is because he knows he'll cry if he does.
Oh, how far he managed to fall...
Training begins the next day, after his last day of class. There's a massive, earthen room underneath Urahara's store and that's where they go, Urahara, his coworker, those kids and him. Ichigo tries to hide how he's panting by time he's reached the bottom of the ladder and flinches only slightly under Urahara's eyes.
Then he's pushed from his body and he never thought he'd have a harder time breathing.
It's worse than in his human body and he can only barely hear Urahara explain why. His chain link, his soul sleep, broken from the attack and rendering him all but a basic soul.
There's a chain coming from his chest, linking him to his body and he doesn't know if he's thankful or not. What if it breaks? At least now, it's like he has some tie to his human body, even if he can see the chain starting to rust in places. His body looks too pale where it lays and he hopes no one else notices.
Then he's running, trying not to be killed by a little girl he's never met before and it doesn't matter that he can't breathe as long as she doesn't hit him. He manages to stay out of her reach, running as fast as he can and he's surprised that it works. Surprised that, as he runs and dodges, he can breath easier and his muscles, previously shaking, are still now. He feels stronger and he takes a chance, whirling around and dodging her strikes like they're nothing.
He lands a hit and she changes, her eyes emptying in a way that's scary and causes Ichigo to freeze. Then his head is ringing and sand falls around him, debris from the rock wall he's been kicked into.
He passes that round. It doesn't stop his world from spinning when he stands upright again.
"Now..." Urahara smiles at him from behind the fan, all the pleasantries from before replaced with malicious amusement and before Ichigo knows it, the other man is there. With an axe.
And it doesn't matter if his soul chain is rusted or not because it's broken now, severed with one heavy chop.
"What..." Ichigo's voice is faint, his eyes wide as he stares at the chain dangling from his chest. Further away, he sees his body and has to choke back a sob. Well. So much for hope.
From what he can see of his body, the hair has faded in color and it's as pale as ever. Even without going to check, even without feeling the extra weight off his shoulders, he knows he can't return to it.
Urahara tells him so and he acts indignant, like how the man expects him to and tries not to feel the relief coursing through him. If Urahara says he can't go back into his body, it won't be a surprise when he can't, will it?
"Your chain of fate will erode from where it's cut," Urahara continues, fan swishing lazily. "When it reaches your chest and disappears entirely, you will become a Hollow." He says it calmly, with just a hint of his usual humor but that doesn't stop the fear that courses through him. Ichigo sputters and Urahara shrugs. "The only way to avoid this is to become a Shinigami," he says, a glint of mischief in his eyes.
Because Ichigo knows how to do that, right. Ichigo wants to scowl and cross his arms but refrains, clenching his hands into fists instead. It doesn't matter that Urahara makes it seem like a choice, this or that, there's only one path he's ever been set on.
"Well?" he says, looking up with a determined spark in his eyes. "What are you waiting for?" Urahara smiles, the grim edge hidden by his fan, and the other man steps forward.
They bind him up like a mummy, toss him into the hole, and begin.
The breaking point is when he gets his powers back.
Really, Ichigo thinks as he lays out on his bed, comfortably back in his Shinigami robes, how could it not be? Even if his body hadn't been utterly failing by that point, his chain of fate had been severed and destroyed. Any attachment to his body had been broken then, shattered like his sword that night.
He tried to go back into his body, after. Tried to hold onto the tiny sliver of hope that his body would hold him.
It didn't.
Urahara noticed right away, of course. Noticed how, when he looked again, Ichigo was just standing next to his body with a pinched look. Saw how relaxed Ichigo looked, how different it was from the times he'd seen the teen as a human. Then he noticed how tan that Ichigo was, how pale his human body was. How the orange of his hair paled in comparison to the orange of his spirit. Noticed, with them next to each other, how sickly his body really was.
And he'd walked over, gently taking Ichigo's arm and steering him away, back up into the shop. He'd given him a gigai, quietly explaining how it works without giving away any of his own feelings. He'd told Ichigo he couldn't return to his body, hadn't he? So it wasn't a surprise and Ichigo just nodded along with the explanations, going along with it and leaving the shop with weights on his shoulders again.
Their training begins tomorrow. Six more days, plus seven to open the gate, then he'll be off.
Ichigo just hopes he's able to return to this world after all is done.
A/N: My Bleach headcanon comes from black k kat's story "Protégé" where Ichigo says: "I've already died. Urahara gave me a gigai to replace my body. Apparently tossing your soul in and out a few hundred times isn't good for your health." Which makes a lot of sense, really. So I wrote this based on that.