If a monster you control is destroyed by battle and sent to the GY: Special Summon 1 "Fireball Token" (Pyro/FIRE/Level 1/ATK 100/DEF 100).
If a monster(s) in your hand and/or field is sent to the GY by an opponent's card effect: Special Summon as many "Fireball Tokens" as possible, up to the number of sent monsters. You can only use this effect of "Graveyard of Wandering Souls" once per turn.