The moment as a storyteller/writer/artist when your character astonishes you with a major reveal -
Me (while puzzling out this particular main character): So, why did you become an assassin, Akira?
Akira Ishikawa: Because Tak died.
Me (internal thought is boggled): Wait - *That* Takeshi?
Akira: Takeshi Ogawa, who else?
Me: I did not see that coming. But why did you -?
Akira: He died and I wasn't there to protect him, and it's his old man's fault. I wanted to kill him for what he did to him.
Me: Did you? Was that your first kill?
Akira: No. The old man cheated us. Got drunk and fell into the river.
Me: So, you were bros with Tak and Eiji?
Akira: Yeah, I was. With Tak before he killed himself. Still am with Eiji.
Me: How'd he take it? Tak's suicide, I mean.
Akira: He was busy. Couldn't even go to the funeral or talk to Ryuichi. I was angry at him, too.
Me: So you became an assassin after that?
Akira: Anger was the only thing I knew. I didn't want people like his old man alive. So I did what I could.
Me: Are you regretting it now?
Akira: I don't know. That's not something I can answer right now.