Spard'a, Bringer of Doom

Flying, Menace, Deathouch
{t}{x}: Spard'a, Bringer of Doom deal X damage to target creature.
{t}{x}: As an additional cost to this ability, sacrifice a creature with toughness 3 or more. Destroy target creature. Spard'a, Bringer of Doom gains toughness equal to targeted creature's power.