
Originally Posted by
AoE
Think it all goes back to what Ulquiorra said honestly. Ichigo's power fluctuates so much that honestly who's to say what's his maximum strength? Even if he's as strong or stronger than Aizen, besides the obvious plotkai that's gonna be invoked, most of his wins came from sheer luck a.k.a "willpower". Also with him being a teenager and being so emotional, I'm guessing he probably won't learn to fully control his power until the Kubo decides to put this manga to an end.
All speculation of course.