Geist of the Lonely Vigil 
Creature — Spirit Cleric
Defender, flying Delirium — This creature can attack as though it didn't have defender as long as there are four or more card types among cards in your graveyard.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL