Activate this card if both players have 5 or more monsters in their GYs; destroy as many monsters on the field as possible, then each player banishes (face-down) as many monsters from their Deck as possible, then you can Special Summon 1 Normal Monster from your GY. Once per turn, during the Standby Phase: Activate this effect; each player can Special Summon 1 monster from their GY, ignoring its Summoning conditions, but banish it when it leaves the field. You can only activate 1 "Underworld Circle" per Duel.