The Blight-Keel

Pirates in your graveyard have Mutate onto
The Blight-Keel {1}{u}{b}

Whenever a creature that was dealt combat damage by The Blight-Keel dies this turn, target player mills equal to that creature's power.

The Blight-Keel can be crewed by exiling any number of creatures with total power 3 or greater from your graveyard.

The Blight-Keel can be your commander