Witch or Thief of Blood making it so even if you do consciously comprehend that they are not your loved one whom you trust, your soul and everything still reacts as if they are. Like say, making it feel like they are your beloved mother while they are slowly and painfuly kill all of your friends. Or like they are your best friend when you are emotionaly vulnerable in order to manipulate you, to control you.
Oh God. Blood or Heart would definitely work, with Blood more as Bonds, the ‘being aware that’s not the case but still feeling like it’ seems like it’d fit just nicely. Stealing the bonds you have with people or changing them, altering your perception of others, your perception of them. Dang.