I second Brandiwyn🎶 's opinion on the redeeming qualities. That always makes me find them more believably.

Since there's an entire novel that you seem pretty familiar with about the Commisioner, I would think you'd want to get into the bandit leader's backstory to try to find a piece that makes them sympathetic, or at least relatable on one level. Like, he can be foul but still like kittens.