Serra Avatar

Serra Avatar's power and toughness are each equal to your life total.
When Serra Avatar is put into a graveyard from anywhere, shuffle it into its owner's library.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Malignus

Malignus's power and toughness are each equal to half the highest life total among your opponents, rounded up.
Damage that would be dealt by this creature can't be prevented.

Brion Stoutarm

Lifelink
{R}, {T}, Sacrifice another creature: Brion Stoutarm deals damage equal to the sacrificed creature's power to target player or planeswalker.