Most multiplayer players are running mass removal in their colors, so if you exile Damnation, Wrath of God, Austere Command and Blasphemous Act you get one for sure
Since poison is his thing, we wanted some sort of life-loss-matters ability
Grand Coliseum Five-color decks and commanders that care about you taking damage will love Grand Coliseum, and its easy to see why
Then for each creature card you own in exile with a memory counter on it, create a tapped and attacking token that's a copy of it
While on the bad guy's side of the struggle, there's a terrifying black reprint, Phyrexian Obliterator
Modal spells have always been popular for their versatility and include many popular Commander staples