Xavier, Psychologically Insane

Deathtouch, Descend 4- If you have four or more permanent cards in your graveyard, put a double strike counter on target creature.
When Xavier, Psychologically Insane enters the battlefield, Deal X damage to every target you don't control. If this would deal damage to any creature, instead prevent that damage and give that creature that many -1/-1 counters instead.

All opponents pack up and move to Pennsylvania.