https://typemoon.fandom.com/wiki/Oberon_Vortigern
Oberon Vortigern is a liar. Everything he says and does is contradictory, so telling the truth is meaningless. Adding to that, he hates and despises everything. Not just humanity, but the very foundation of the world itself. Don't expect him to play nice with you on the first meeting, expect to be antagonized, criticized, and at worst shown little interest.