Looking for a book that has a major character with similar Vibes to Alastor from Hazbein Hotel. (With better writing) False friendliness & manipulation. Being “on the MC’s side” while having their own agenda behind the scenes.

I want to write a character like this for my own project. Having more examples would definitely help with that.

I want a character who has schemes and designs and is using the main characters to accomplish those goals, but isn't being obvious about it.

The main character is know that they are scheming and even suspicious maybe but they genuinely think that they are on their side, as much as they can be on anyone's side.

The audience might not even be sure whose side this character is on the glimpses we get of their schemes don't clarify their intentions.