Slifer the Sky Dragon

Divine Offering 3 (As an additional cost to cast this creature, sacrifice three creatures. This spell can't be countered.)
Flying, vigilance, Protection from instant and sorcery spells.
Slifer gets +2/+0 for each card in your hand.
Whenever a creatures enters under an opponents control, it gets -2/-0 until end of turn. If this effect would reduce its power below 1, destroy that creature instead.