Mythical Bestiamorph (SR08-EN035) [Structure Deck: Order of the Spellcasters]

Each time an opponent's monster effect is activated, place 1 Spell Counter on this card when that effect resolves. You can send this card with 6 or more Spell Counters to the GY; add 1 Spell from your Deck to your hand. You can only use this effect of "Mythical Bestiamorph" once per turn.