Kayn,Shadow Assassin

Kayn,Shadow Assassin can't be block.
Whenever Kayn, Shadow Assassin enters the battlefield tap all creatures your opponent controls.
{u}{u}You gain control of target creature until your next end step.
{b}{x}Kayn,Shadow Assassin deals {x} to target creature.
"The Darkin is dead now,I killed him!"
Kayn,Shadow Assassin