At the time no one ever questioned why I didn't answer that purple bastard's call. They didn't have a reason to, I was just a hollow to them, but the old man knew better. He asked later, as if it had only just occurred to him that I should have been called the first time and didn't answer. He wasn't wrong, I heard the call and I didn't answer it.

Why?

Hmph, 'cause I ain't stupid like the others.

Don't believe me? I know that I'm a manifestation of his desire to fight, filled to the brim with the convictions that make him fight. He wants nothing more than to protect, so I reflect that in a purer, simpler way. To me the world is black and white. What I protect is him, from the enemies he picks fights with and the loss that would make him curl up and die. And to protect him I eliminate the threats, no hesitation or second thoughts. He's soft, merciful to the point of foolishness. Sometimes he forgets what it means to fight and I have to remind him that he can't afford to be weak on the path he's chosen.

So when the purple bastard started calling, trying to tell me that I'd be better off on my own, better off fighting against him, I didn't buy it for a second. Who's gonna save his pathetic ass if I'm not around? Besides, unlike the others, I've known what it's like to be the king, even if only temporarily, so I knew that killing him like purple face wanted was killing myself.

I can wear the crown, but never own it.

But I don't need to own it. All I need is for the guy wearing it to have a strong hand and not give up. Sure as hell makes my job easier when he's not whining like a little bitch and rolling over for any bastard to stab. When he wimps out, doesn't know how to pull out the strength he needs, it's my turn to take the crown and save his stupid life. Then he gets all mad and scared that I came out, but it makes his will stronger. If he has to be scared of me to keep that stronger state of mind, then so be it. All I ask is that he doesn't give in to the fear.

So I couldn't ditch him for some sham crown. Can't say as much for the old man. He ran right on out, thinking death because he hadn't mastered the powers he'd been shown was acceptable. The backstabbing bastard. I knew he would hesitate more than ever fighting the old man like that. He had already hesitated fighting the little ice queen's blade, so of course the idiot would hesitate in fighting his own. I took over when the idiot didn't fight back, didn't even try to draw on my strength.

I was winning, of course. I was always the stronger blade, but then the idiot decided to assert his authority. It is both good and annoying as hell when he gets his act together. He gets his head in the fight, but he still doesn't go for the kill. He is capable of the kill. Wouldn't have been able to beat me out of protecting his stupid ass if he wasn't, but he always shies away, hesitates to put down the threat. So I'm left to clean up his damn messes or at least bring them down so that he can win with his mushy soft-hearted fighting.

Then the purple bastard came in to invite me out again.

He dragged me out and tried his warping call, but it didn't do a damn thing to me. Like I said, I ain't stupid like the others. There was no damn reason to listen, so I set to kicking his stupid purple ass, out of our world or to death, either one worked. I was winning that one too until the damn bastard cheated and tied me up with all those invisible hands. Bitch was scared he couldn't win in a straight up fight. Getting my ass saved by him was a damn embarrassment, but it was good to see that he wasn't so stupid as to let his own powers get destroyed. It's nice to get acknowledged every now and then, but tell him and I'll rip your spine out through your nose.

After that we fought together as zanpakuto and shinigami without any interference for the first time. Bitch slapped the old man, limited Bankai and all, with one shikai Getsuga Tensho when he finished adjusting to fighting with just me. Guess an ass kicking murder was all that needed to happen to snap the old man out from under purple face's control and it was back to the regular damn limited contact.

Unthanked work, that's what I do. I protect him by tearing skin, breaking bone, shredding flesh. It's what I know and embody, the final solution to all threats: death. He tempers me by force of will, but he will never erase me. He knows that he needs me to continue living his chosen path because without me, he wouldn't be able to protect anymore.

So I was asked why and the answer was simple:

I'm a part of Ichigo and I could never kill him.

Author's Note

I was randomly inspired to do an introspection of hollow Zangetsu and a more canonical reason for why he didn't answer Muramasa's call to arms in the Zanpakuto Rebellion filler. This is filled with a lot of my thinking on how he presents himself to Ichigo after factoring in his true nature. If you want more of that reasoning, pm me or something. I'm always happy to talk the finer points of Bleach.

Please comment/review.