Hey, I never said Mitsuzane wasn't a bastard; he is ; I was only talking about that precise fight; besides, unlike what other people say, I don't think he's truly the Overlord's ally: the main reason he doesn't fight them is because he's convinced it's useless.
You're right that it's Mitsuzane's recent actions which started the fight; but I don't think that Takatora's choice to stop Mitsuzane (a direct fight between the two) was the good one ; from what I've understood, the core problem with Mitsuzane is that he feels that the situation is hopeless, and that trying to work with the Overlords is the only way to save at least part of humanity. In Micchy's eyes, anyone who opposes the Overlords is a fool who's only making things worse, and yes, he will kill those people because he thinks they're dangerous; it's not just a crazy feeling : he's a deep rooted belief.
The only way to stop Mitsuzane is to make him understand that his current choices are foolish; and it's not gonna be easy, because given how powerful are the Overlords, Micchy's attitude isn't completely without reason.