The Dark

Psychic Allergy

Choose a color when casting Psychic Allergy. During opponent's upkeep, Psychic Allergy does 1 damage to opponent for each card of this color that he or she controls. Sacrifice two islands during your upkeep or Psychic Allergy is destroyed.

As Psychic Allergy enters, choose a color.
At the beginning of each opponent's upkeep, Psychic Allergy deals X damage to that player, where X is the number of nontoken permanents of the chosen color they control.
At the beginning of your upkeep, destroy Psychic Allergy unless you sacrifice two Islands.