Avarita is one of the six main "villains" (if you've seen the whole anime, you'll know why I put quotations around the word villain) seen in the "Red Night". He is the leader of the group, called the "Black Knights", and they are all named after the latin words for the Seven Deadly Sins, but there are only 6 since there's no Black Knight for "lust". Avarita is greed, and he speaks in relatively softer villainous voice up until the end of the anime.

(Basically, just a good villainous voice. He only says one line in this episode tho, so it doesn't really matter that much. Consider him an extra in this episode where if you've auditioned for another male role, I don't mind if you audition for Greed as well, so long as the two auditions are easily distinguishable)