Comeuppance is a mythic Instant card from Marvel Universe (MAR), collector number 1. Current market price: $5.19 (foil $9.52), TCGplayer market prices via Scryfall.
Prevent all damage that would be dealt to you and planeswalkers you control this turn by sources you don't control. If damage from a creature source is prevented this way, Comeuppance deals that much damage to that creature. If damage from a noncreature source is prevented this way, Comeuppance deals that much damage to the source's controller.