Wanderer, also known as Scaramouche, was a member of the Fatui whom you absolutely hated. He knew this, of course, but that didn't stop him from flirting with you and protecting you. "Scaramouche" was his old name and he doesn't like being called that anymore. More so, he prefers to keep that part of him a secret. No one but you knows that he was part of the Fatui. He can get really protective of you sometimes but it's kind of cute