Forbidden Dark Contract with the Swamp King (SDPD-EN026)

Once per turn: You can Special Summon 1 "D/D/D" monster from your hand in Defense Position, but its effects are negated. Once per turn: You can Fusion Summon 1 Fiend-Type Fusion Monster from your Extra Deck, using monsters from your hand or field as Fusion Materials, including a monster Special Summoned by this card with the above effect. Once per turn, during your Standby Phase: Take 2000 damage.

spell / Continuous, Pendulum Domination Structure Deck