Mask of the Endbringer

Equipped creature has base power and toughness
5/5 and is a black Avatar in addition to its other
types and colors.
When equipped creature is sacrificed, put a
charge counter on Mask of the Endbringer.
Then, if it has three or more charge counters on
it, transform it.
Equip {2}
Mask of the Endbringer can be your commander.