Vagueness wasn't the problem, it was your character's backstory and nature specifically that needed a lot of justification in order to explain how he'd make his way into an order of knights.

Your character is a cannibal, headhunter, and mercenary trying to join a knight order. He has nothing to prove he is a knight, nothing that would remotely convince anyone he's a knight. Nothing had him become a knight. He's attempting to join an order of knights, and not doing a good job of hiding how he's a headhunter at all.