User blog comment:Zulfiq/Post Dangai Training Ichigo VS Post Squad Zero Vacation Ichigo/@comment-24913480-20140917092013

That is a good question. Dangai Ichigo curbstomped Transcendent Aizen even before he activated Mugetsu (and at that point Aizen was confident he could defeat the Zero Squad and the Soul King by himself but he could have been overestimating his own power). It's hard to say if the current Ichigo is as strong as Dangai Ichigo but I don't think so. Right now, Ichigo is using his real zanpakuto and has unlocked his quincy power (I think) but Dangai Ichigo FUSED with both his zanpakuto and his quincy powers (that's what hollow zangetsu was, I believe) and that fusion made him much stronger than he is now. So strong he transcended Aizen. Maybe he can do that again, maybe not. Maybe I'm completely wrong. I'll let Kubo decide.