Old King Allant

Vigilance, Deathtouch, Haste
Wind Slash: {t} You may target a creature or
plains walker.
Soulsucker: {t}, {x}{w}{b} To destroy target
creature or plains walker where X is the amount
of damage this attack will deal to the opponent
if there are no creatures or plains walkers
they control left. (If there are no creatures or
plainswalkers the opponent controls you will
also take the same amount of damage.)