Nightmare King Grimm

Dream (Discard a card: This card can be played
from your graveyard this turn.)

When Nightmare King Grimm enters or leaves the
battlefield, you gain 2 life and each player discards
a card.

If you would discard a card, instead you may pay 5 life. If you do, cast that card without paying its
mana cost. This ability triggers once each turn.