Grimnir, a being created by one of the 41 supreme beings in the Tomb of Nazarick, Ulbert Alain Odle. He along with several other beings were made for the sole purpose of being Nazaricks last line of defense known as the 8th Floor Hierarchy. The guardians of the 8th floor were said to have a combined power greater than all of Nazarick itself and once stopped an alliance of guilds comprising 1500 people.
At some point during the new age, Grimnir defected from Nazarick after the 41 Supreme Beings had vanished and before Mononga returned, thinking his creators abandoned them. After leaving, Grimnir took up a different name and eventually became know as the Allfather. He possesses two world items known as Gungnir and The Poetic Edda.
In the current era of the new world he resides in his kingdom of Asgardea and has become aware of Nazarick and assumes one of the 41 supreme beings is the “sorcerer king”. Knowing from personal experience what terrible things Nazarick is capable of led him to side himself with the 13 heroes of the new world.