Remembering the chapter 397, I wonder if Aizen foresaw current events, when developing Ichigo I can go as far as assuming that Aizen knowingly destroyed Cleaner to let him train and develop further, as it was mentioned by few other people, before. Then use FGT to defeat him, since Aizen definitely knew about Fullbringers, together with rest of SS, and possibly knew about FGT.
+ Aizen sentence of "You're son of a shinigami and a ". Combine that with what ppl here said about who Ichigo's mother can be. (although ye, there was a confusion with 2 different phrases in 2 chapters.)
Guess there's a very good chance of seeing more "Just as planned" moments in the future.... and then we end up with Aizen being Spirit king's agent or being manipulated by "it", that saw what was coming and decided to prepare. (after all, Quincies with their ability and goals are an ultimate threat to Spirit world) Aizen didn't look too frustrated when he was sentenced to 20k years.
But I guess it's just my imagination.
