aizen fusing with his zan is still just theory.
In my opinion, the way this whole event is presented has two possible explanations.
1. aizen fused with his zan --> use the powers of his "fused" zan on bach --> distorted bach's perception of time
2. aizen didn't fuse with his zan (thus being wrong in the the last panels of his fight with ichigo)/ lost his zan because he lost his power --> used his rhetoric skills/ his reiatsu properties (the same way hitsugaya's were able to create ice) or he managed to manifest his zanpakuto's powers without a zanpakuto --> distorted bach's perception of time
Since the scenes that give the readers clues are open to interpretation and are thus ambiguous, until something is stated so it can confirm which possible scenario is the correct one, everything we argue about is in the sphere of hypothesis.
I would even add 3 - hogyoku discarded Aizen's zanpakuto because the evolution gave him the ability to channel KS through his own body instead of having to rely on the zan to use it. Since the zanpakuto itself is really just a tool that the shinigami power with their own souls, Aizen should should have never lost the ability to use KS, unless hokgyoku somehow replaced the part of his soul that contained the powers.
Edited by Madwillionaire, 20 July 2016 - 08:47 AM.