Habsien, Overlord

First strike, Haste
All non-legendary creatures have Mercenary 3
(at the beginning of any combat step, a player may
pay {3}. If they do so, they gain control of this
creature)
Whenever an opponent pays the Mercenary cost
for a creature you control, tap that creature.
Traitors! Bastards! Your death's shall be agonizing
and slow!