The Battle of Hidefall occurred in Hidefall in Libaterra in 1017 AE. It began when Gilgamesh, posing as Irvin Finian, tried to kidnap Haruko Mizushima, who was a guest of the Union Workers, from her room until he was intercepted by the Union as well as Haruko's self-appointed guardians known as the Fellowship of Hidefall. During the battle with Gilgamesh, the real Irvin and Katsutoshi Kobayashi, using the title of Izanagi, appeared and used the chaos to their advantage to injure Gilgamesh and steal Haruko from him and the Union before fleeing through a portal into the Void. This made the fellowship, who by the time had come to believe that Gilgamesh was Haruko's mate, to join forces and chase after the kidnappers who had fled to Malperdy.