Part of me wonders if that was supposed to be a part of the "they're dealing with issues you guys don't know about!" bit, but you'd probably want to establish, or better yet hint at, that sort of dynamic during his first introduction with the rest of the family. All he really seems to be is more of an authoritarian/disciplinarian type, which is hardly uncommon, especially (if we're generalizing) in East Asian families. His first scene doesn't have to be beating them or stumbling around as a worthless drunkard, that'd be too on-the-nose, but nothing presented in the first chapter there really indicates to me any flaw other than "says (hilarious) mean things about the protagonist, who is black."