Board Thread:General Discussion/@comment-4976518-20140808063123/@comment-11444045-20160311053913

Not 100% related but how did aizen get stronger during the 2 years he was imprisoned? don't you need to train for that to happen or was this a byproduct of the hogyoku?

I suppose given how powerful he was with reiatsu and abilities he didn't see the need to use it. But the bankai having drawbacks is a viable reason not to use it.