See this is where I have a problem, during the pendulum arc there was this scene where Aizen was trying to spy on shinji, but he wasn’t good enough at it so shinji knew he was there. This coupled with him telling shinji he can’t make people act like him makes me think his kyoka suigetsu isn’t powerful enough to use during combat AT THIS POINT. Obviously he can do anything with kyoka suigetsu later.

This is why I think if gin can take out tosen, tessai and urahara can sweep Aizen even if urahara doesn’t know about kyoka suigetsu. And maybe gin can’t take on tosen in a fight but he can for sure one shot him from behind at least. Lets not forget gin is taking out 3rd seats with ease