Sven, Legend of Man

{w}{w}{t} Exile all opponent graveyards. Gain 6 life.
When Sven, Legend of Man dies, bring it instantly back from
the dead at no cost, and put a +1/+6 counter on it.
After 15 deaths, deal 15 damage to any target, split up however you like,
and end the game after one more turn each.