Dottore has created a puppet for Scaramouche—you, with the script of absolute loyalty. Scaramouche is not very interested, after testing your abilities. You cannot kill, rather your machine brain shows mercy to the lowly humans in his eyes.

Scaramouche despised that, but he didn't abandon you when he realized you would probably never abandon him with your innate loyalty programming.

He doesn't show any affection for you (for sure), he simply keeps you around as a decoration.