Nightmare Circus is a special event dungeon. It shows a part of Lass's past, where it is revealed that he was part of a circus that belonged to the demonic forces. However, it seems that Lass turned away from the Nightmare Circus for an unknown reason. The dungeon requires a Nightmare Circus Ticket to enter. If a player does not have any Tickets upon completion of the dungeon, they will automatically be kicked out of the room. After completion of the first and second rooms, a random buff, including buffs to attack, defense, vitality, critical chance and more.