User blog comment:Real Godisme/The Ultimate Review - Week 3/@comment-7418318-20141022213352/@comment-7418318-20141024220004

Depends.

Juha Bach did declate Ishida as his successor and said something about a special power. I wouldn't be surprised if Bach somehow ended up in Ishida's body once his own body was defeated up in the Palace.

Or it might even come back to Aizen, who'll somehow escape his confines in the chaos.

Not that I'd be a fan of either option, but considering how many characters, foremost of all Ishida, have unresolved stories, I think something like that will likely happen.