Strategies that leave you as the last player standing are paramount in a multiplayer environment
Sultai Arisen The ability to pull cards from your graveyard is inherently powerful and both commanders, Kotis, Sibsig Champion and Teval, the Balanced Scale let you do that every turn
Evelyn, the Covetous Evelyn, the Covetous would be my choice for a vampire-typal commander simply because Im a sucker for card draw in the command zone
Basically the way it works, as is printed on the card, is that you can cast it when you declare your attackers, turn your attacking creatures face-down and then shuffle them around
Heritage Druid might be the way the Elves deck breaks it, but I could see a world where you play Glimpse of Nature and a bunch of free artifact creatures