Berserk lover
Berserk is a highly overrated anime and manga series. The term "Berserk lover" refers to people who think that their tastes are better than others and they may believe that Berserk is the best anime ever. The term may also be considered synonymous to "Flat Earther" for this reason because both are, essentially, describing stupid people.
He won't like quality anime, he's a Berserk lover.