The Amulet was created by the Æsir during the Isu Era to open the door to Let its user train inside a mind realm with no fear of injury. The Isu device was also used as a key to open the gate to Freyja's Cave. Some time after its creation, it was taken to Freyja's Cave and after locking the Odin's Eye inside it was used to close the door. As the millennia passed after the Great Catastrophe, the Vault became overgrown in vegetation and earth, and its location was lost to memory.
Sometime in the 870s, a meteor landed in the Viking settlement of Ravensthorpe in Mercia. The jarlskona Eivor Varinsdottir of the Raven Clan went to investigate the crash site and saw the woman Hildiran also inspecting it after the impact revealed the door to Freyja's Cave. Hildiran convinced Eivor to let her stay and after a short fight showed her the Amulet, activating the device both Eivor and Hildiran began a fight in the minds realm. After the fighting had stopped they were brought back to the normal world. Hildiran taught Eivor the art of Hugrheim, a battle meditation named for the eponymous mental realm where warriors knowledgeable of the technique could train without risk of injury which they had just participated in. She then told the amazed Eivor that only after filling a special Amulet with the energy from battle meditation could she hope to open the door.
Eivor quickly completed a series of meditation challenges at various statues of Freyja situated throughout England and brought the filled amulet back to Hildiran, who had spent much of her time clearing away the rubble from the door. Opening the gate, the women entered a vast stone room. Inside were three large archways carved into the walls, gateways to nowhere that impossibly contained cold fog spilling over stalactites and stalagmites, rubble covered in still-living vines, and a falling river of fire. The chamber was flooded in ankle-deep water save for a single stone path to the center, where Odin's Eye rested on a small plinth.
Hildiran spotted Odin's Eye on the pedestal and told Eivor to grab it. As the Viking stepped forward, the Eye activated, and the amulet with it. The Odin's eye outer shell glowing white and spinning as it briefly hovered and projected glyphs, before deactivating and settling back in its spot. Hildiran demanded Eivor give her the device, Eivor put the amulet back into her satchel and gave Hildiran the eye.
- The Amulet features three Norse runes engraved on it, either these symbols are Isu in origin and then used in the millennia after by the Norse or they were added to the device at a later date by the Norse.
- Assassin's Creed: Valhalla – Mastery Challenge