Ashened to Endlessness

“During the Main Phase: You can Fusion Summon 1 Pyro Fusion Monster from your Extra Deck using monsters from either field as material, including "Veidos the Eruption Dragon of Extinction", and if you do, it gains 500 ATK for each material used. You can banish this card and 1 DARK Pyro monster from your GY; all monsters your opponent currently controls become Pyro until the end of this turn. You can only use each effect of "Ashened to Endlessness" once per turn.”