Frostmourne

Obey! — Whenever Frostmourne enters the battlefield, attach it to target creature you don't
own, gain control of target creature as long as Frostmourne is attached to that creature.
Whispers of The Lich King — Equipped creature
gains +3/+3 and has "{3}, Sacrifice this creature:
Target player loses 2 life and draws 2 cards. Any
player may activate this ability."
{u}{b}: Return Frostmourne to its owner's hand.