Khamûl, Shadow of the East

Morgul Blade (If a creature that was dealt combat damage by this creature dies, instead it becomes a
2/2 black Wraith creature token with lifelink under your control.)
This spell costs {x} less to cast, where X is the number of creature cards in your graveyard.
At the beginning of your upkeep, you may sacrifice a creature. If you do: put X +1/+1 counters on Khamûl, where X is the number of creature cards in your graveyard.