Board Thread:General Discussion/@comment-4976518-20140808063123/@comment-10330822-20191026174553

I like that idea as well. Honestly, if Kubo was trying to find an excuse for why Aizen never used his Bankai, even when fighting people who should be stronger than him, I feel it has to be because it was either too risky or impractical.

However, I would still side on impractical over risky, because Aizen had a massive amount of reiatsu and was pretty much immortal. So I question why a Bankai would not be used even if it was risky, unless, like I said, it just wasn't helpful.