Mordekaiser, The Indomitable

Indestructable
You may cast Mordekaiser from exile for
{10}{b}{b}.
Whenever a creature an opponent controls dies,
you may pay {b}. If you do, exile that creature.
You may cast creatures exiled this way at any
time for {x}, {x} being that creatures converted
mana cost. Mordekaiser gets a +1/+1 counter for
each creature in exile.
"Unfettered by mortality"