A 2/2 Legendary creature Human Cleric with lifelink that costs two generic and one white mana, whenever you gain life you place a +1/+1 counter on Aerith Gainsborough
Then separate anything you might actually play
Theres a third option of dealing four damage to a player or planeswalker, but that pales in comparison to the other two
(9/25/2006) If either target is illegal at the time the ability resolves (whether because it has left the battlefield, because it has gained Shroud or Protection, or for any other reason), the ability taps the remaining target, but no damage is dealt
Old friend from Theros block
This difference puts you in a reactive, rather than proactive, role, a position to avoid during your I Win turn