In Wake of The Void

This artifact can't be removed from play.
Every upkeep each player sacrifices one of each
card type, discards 2 cards, takes 3 damage, puts
the top four cards of their library into their
graveyard, and exiles all cards in their graveyard.
"An entity created from darkness only to devour. A
great threat to the worlds balance, and if it should
enter your world know you will turn to dust as the
monster devours everthing in its wake."