March of the Damned

As March of the Damned enters the battlefield,
Commit all creature cards in all graveyards.
(Exile them until March of the Damned leaves the battlefield. When it does, shuffle them into their
owners' libraries.)
Whenever a creature card is put into a graveyard
from anywhere, Commit it.
March of the Damned gets +1/+1 for each card Committed to it.