Hero's Voyage

Whenever a creature you control deals lethal damage, put a quest counter on Hero's Voyage.
At the beginning of your end step, as long as Hero's Voyage has five or more quest counters on it, you may put three +1/+1 counters on all creatures you control, deal 3 damage to all opponents and all creatures they control, and gain 10 life. If you do, Exile Hero's Voyage.