Diabolos, King of the Abyss (FOTB-EN061) - Force of the Breaker Unlimited

This card cannot be Special Summoned. If you Tribute Summon this card, the Tributes must be DARK. This card cannot be Tributed by a card's effect. During your opponent's Draw Phase, before their draw, look at the top card of their Deck, then put that card on the top or the bottom of their Deck.