Solphim, Mayhem Dominus is a mythic Legendary Creature — Phyrexian Horror card from Phyrexia: All Will Be One Promos (PONE), collector number 150p. Current market price: $35.01 (foil $64.38), TCGplayer market prices via Scryfall.
If a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals double that damage to that player or permanent instead. {1}{R/P}{R/P}, Discard two cards: Put an indestructible counter on Solphim. ({R/P} can be paid with either {R} or 2 life.)