Scourge of the Underworld

Deceit (This creature deals damage to players in form of putting that many cards from the top of his/her library into his/her graveyard.)
Scourge of the underworld costs {1} less to cast for each color among mana costs on cards you control in your graveyard.
At the beginning of your end step, if three or more card types were put into an opponent's graveyard from their library, draw a card.