Overlord: World of Gown

Before the Shutdown, Momonga finds a Secret Boss which drops a Mysterious Item. But when he fuses this Item with the Staff of Ainz Ooal Gown, he creates an Item beyond that of a Guild Weapon. The devs seek to destroy him for using this newly found glitch, but they were too late. Ainz Ooal Gown has already descended onto the New World. This time, indestructible.