Feather, Diabolic Tactician

Flying
Whenever Feather, Diabolic Tactician deals
combat damage to a player, exile the top card of
that player's library face down. Then you may
sacrifice Feather, Diabolic Tactician. If you do,
look at and choose one of the face down exiled
cards. You may cast that card for as long as it
remains exiled. Then create a treasure token.
"Coo-Coo on this!"