Elia, Fallen Seductress

+1: Take control of target creature until the beginning of your next turn. You lose life equal to it's converted mana cost.
-4: Creatures you control get +X/+X and lifelink until he end of the turn, where X is half of your life total, rounded down.
-7: Take control of all creatures. Then you gain life equal to the amount of creatures you control.