Raviel, Lord of Phantasms (MP21-EN254) - Prismatic Secret Rare

Cannot be Normal Summoned/Set. Must be Special Summoned (from your hand) by Tributing 3 Fiend monsters. Each time your opponent Normal Summons a monster: Special Summon 1 "Phantasm Token" (Fiend/DARK/Level 1/ATK 1000/DEF 1000), but it cannot declare an attack. Once per turn: You can Tribute 1 monster; this card gains ATK equal to the Tributed monster's original ATK, until the end of this turn.