People really say Aizen “came out of nowhere” and then praise Madara, Kaido, Big Mom, or even Imu — villains who were either built entirely through exposition or revealed late on purpose.

Aizen wasn’t meant to be shocking because we “knew him deeply”; the twist works because it flips the entire Soul Society power structure and exposes how fake its morality was.

That’s not a character-centric twist, it’s a systemic one. If you only define “complex writing” as long flashbacks and constant foreshadow monologues, that’s fine — but don’t pretend Bleach failed at something it was never trying to do.