Cocytus is the guardian of the Fifth floor of Nazarick. An insectoid heteromorph, he was created by Warrior Takemikazuchi to be an honourable warrior and is tasked with keeping a cache of powerful weapons for Nazarick. He has a neutral alignment, which stands out against the many evil entities in Nazarick. An extremely skilled fighter, Cocytus is an expert at selecting the right combination of weapons for the fight, and dealing huge amounts of damage quickly. With the help of his extra arms, he is capable of wielding four of his twenty-one weapons at once, allowing him to deal the highest damage per second of any floor guardian.