Just saying: if all he wanted was to show off his power, and make a living out of it, doing whatever he wanted --- he doesn't need to become a bandit to do that. Being the head of a legit merc group is enough.
With enough power and authority, which can probably easily achieved with his talent, he could be well renowned enough so his behavior is irrelevant.
I.E: You want to kill people and flex your muscles? Don't need to be a criminal to do that.
It'd be different if he wanted to be a mafioso boss, but that's not really it.