Oberon Vortigern. The mastermind behind all of the trategies in the Lostbelt of Britain. Manipulated Aurora into killing Queen Morgan le Fay. Pretended to be the ally Artoria Caster and Chaldea under the Alias of "Oberon" (the King of Fairies). Encouraged Artoria Caster into becoming the Child of Prophecy and defeating Cernunnos. And once he got rid of Morgan and Cernunnos, without anyone to oppose him, he could finally create "The Insect of Abyss" in order to destroy the Lostbelt of Britain