Castle Doom is a rare Land card from Marvel Super Heroes (MSH), collector number 263. Current market price: $0.37 (foil $0.92), TCGplayer market prices via Scryfall.
{T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast an artifact spell. {3}, {T}, Sacrifice an artifact: Create a 3/3 colorless Robot Villain artifact creature token named Doombot. Activate only as a sorcery.