Beo is an incarnated Elemental and Phantasmal Beast that has existed since long ago but at some point fell as a droplet in the werewolf village in the eighteenth century. He was brought to life through the folklore and tradition of the people from the werewolf village. He was found in a cave by a group of werewolves and was well received by their village. Due to all werewolves having been descended from a single golden werewolf they revered him because they believed that he would bring about a revival of their species that had been in decline since their peak long ago. There had not been a single golden werewolf born since the beginning so all of the kings among them had been silver. They gave him the name Lugh after a sun god so that he would bring about their revival. Upon finding out that Lugh doesnt age and has no gender he became ostracized by the village because they discovered that he would not bring about their revival and was not even a real werewolf in the first place. They eventually sold him to Touko Aozaki because of this and she gave him the name Beowulf. She does not have a binding magecraft that could possibly restrain him but he is attracted to her because she has a good scent and for her promise to let him fight the greatest Mystery. They went on a number of exploits across Europe and he remained undefeated throughout them. Some involved a train that collects Mystic Eyes an ancient giant octopus living in the North Sea the Bermuda triangle which leads to another world and an Elder Title Dead Apostle Ancestor.