>>280541963 (OP)
It's objectively bad writing, but fun.
Your whole fucking series, 400 chapters by this point, have been devoted to THIS villain. You can't just pull a One Punch Man on it...
And admittedly, it was full as hell. I laughed and got hyped tons watching Aizen babble about things he didn't actually understand while pretending he's still stronger (and later equal) to Ichigo while he just stares unamused.
But Ichigo's last fight against Ulquiorra was already this. A big powerup and stomping the unbeatable enemy. The manga was even worse, the anime added a couple of traded hits to make it seem more even.
Kubo REALLY likes his one-sided fights apparently. Also it made zero sense that Ichigo's training would shoot him past every Captain, his mentors, Yamamoto himself, and Aizen after 3 or 4 godlike evolutions to such a degree. It looked like Ichigo had infinite power and was breaking the 4th wall or something, hello? Aizen was the one with the omnipotent device etched into him.
Ichigo was beyond that and even after Aizen evolves one more time, he still can't feel Ichigo's presence. This is pure asspull writing Kubo on a whim decided that Kurosaki's true power was being an omnipotent God or something and rightfully he pretends that never happened during the final arc because the Ichigo from that fight could just stand still tanking every enemy and wiping them all out in 0.001 seconds.
At most let Ichigo slowly dominate the fight against Butterflyzen similar to SSJ Goku VS Frieza, and once Aizen evolves to Monster form have things get dire for Ichigo until he decides to sacrifice all or his power for Mugetsu to end this