@Daz:
Other than the fact that he's an absurd ManBearPig chosen one, I've always been annoyed that Ichigos myriad bullshit powerups boil down to "MOAR BLUNT FORCE". Just watch as Bach falls victim to the same outcome as Aizen: Insanely broken, super-strong being with mind-boggling reality warping powers neglect to make good use of said reality warping powers, and gets taken out by the power of SWORD BEAMS to the FACE YEAH. In a series where transformations upgrade you from "shoots piercing beams" to "Teleporting intangible angel sock which bombards you with beams", All Ichigo knows is cutting stuff and, and cutting stuff faster.
Don't forget another last minute training that will put Ichigo leagues above Bach, where his strongest attack barely does anything to him. Then Ichigo will do another transformation which will make him even more powerful at the expense of him losing his powers.
That was the biggest problem I had with the end of Aizen stuff. Ichigo clearly outclassed Aizen but he decided to go for his final form which made him lose his powers. Seems like Ichigo should've fought in his form at the time, and if things kept getting worse he could go for the last resort. Then again, the whole Deicide stuff was Aizen getting more powerful even though he was above everyone, so why not Ichigo. Only Ichigo got downgraded after regaining his powers while Aizen got a power up and a chair, a chair that can withstand his bullshit.
Maybe that's why he hasn't been shown again. No one could stand up to him, but the chair survived everything. Aizen realized that the chair was to be his companion and that he left to be forever with his friend the chair. However, Bach is too powerful, and they must find something to hit Bach with to win. The chair realizes that his friend Aizen would die if Bach reigned, so it's up to it to take on Bach. It falls on Bach at max velocity, which Bach doesn't see coming because he can only see the future when it doesn't involve inanimate objects. Everyone celebrates and honors the chair, and Aizen finds the error of his way because of his friend the chair.
Then Tsukishima cries as he realizes, that this would totally fly in a book, and his one reason to show up again will be fulfilled.