Author's Note: This came from a discussion between me and my brother. Sorta AU. Think of this as a Shinigami Illustrated! Golden! at the end of an episode.
"You're too naive." Yamamoto growled.
Aizen stared at the captain-commander in shock as the old man uttered his next words:
"Hado 96, Ittō Kasō."
A pillar of spiritual pressure enveloped the area around Yamamoto.
A short distance away, Aizen appears out of a flash step with slightly singed clothes.
Aizen couldn't believe it. He knew that Yamamoto knows kido that well to use a forbidden kido, but he didn't expect Yamamoto to actually use it. Genryuūsai Yamamoto, the Captain-Commander and arguably the most stubborn in keeping to the law, actually used a forbidden kido.
Aizen paused to think about that. He was actually powerful enough a villain to make Yamamoto use a forbidden kido. Aizen pushed Yamamoto, the most powerful shinigami, to break the law in order to stop Aizen.
Aizen smirked. Then he did a little victory dance, singing, "I made Yamamoto break a law!"
That little act shocked the injured captains present and made them question whether this was a hallucination or not.