Lair of Darkness (EGS1-EN032) - Egyptian God Deck: Slifer the Sky Dragon Unlimited

All face-up monsters on the field become DARK. Once per turn, if you would Tribute a monster you control to activate a card effect, you can Tribute 1 DARK monster your opponent controls, even though you do not control it. Once per turn, during the End Phase: Special Summon as many "Torment Tokens" (Fiend/DARK/Level 3/ATK 1000/DEF 1000) as possible to the turn player's field in Defense Position, up to the number of monsters Tributed this turn while this card was face-up.