I actually really like the faces. They were made for the game and exactly what I asked for. ^.^ Maybe I'll try add a bit more detail to them, though. Like, one extra colour.
Pro tip: There aren't too many duels in the game, but each one can gain you a new skill and different cutscene depending on whether you win or not. Yes, with one exception, you can lose all the duels and still carry on with the story... though it's better if you win them. And each character has at least one duel each.