Free Commander event played with your own deck and normal rules, except that at the start of a game you get one of several cards based on classic Magic villains; this gives you an alternate win condition, which is kept secret until it triggers—at which point the other players must stop the villain before each of them loses at the end of their next turn. Everyone gets a promo pack plus a set of the event materials that supports four players, so you can keep using the variant whenever you like.