Volcanic Doomfire (Secret Rare) (SGX1-ENH01) - Speed Duel GX: Duel Academy Box 1st Edition

This card cannot be Normal Summoned or Set. This card can only be Special Summoned by sending 1 face-up "Tri-Blaze Accelerator" you control to the Graveyard. During your opponent's Battle Phase, your opponent must attack this monster with any Attack Position monsters they control. When this card destroys a monster and sends it to the Graveyard, destroy all monsters your opponent controls and inflict 500 damage to your opponent for each monster destroyed by this effect.