Powersink Stone (STBL-EN078) - Starstrike Blast Unlimited

Each time the effect of an Effect Monster is activated, place 1 Spellstone Counter on this card (max. 2). While there are 2 Spellstone Counters on this card, face-up Effect Monsters on the field cannot activate their effects, and their effects are negated. During the End Phase, remove all Spellstone Counters on this card.