Masked HERO Blast (TOCH-EN047) - Toon Chaos 1st Edition

Must be Special Summoned with "Mask Change". If this card is Special Summoned: You can target 1 face-up monster your opponent controls; its ATK becomes half its current ATK. Once per turn (Quick Effect): You can pay 500 LP, then target 1 Spell/Trap your opponent controls; return it to the hand.