Closest I’ve done so far is Filli, who joined my MCs team while he was in the slave pits. She’s a mutant slave soldier, kidnapped as a child and forced to serve as a guard and warrior for a dark elf noble house. She’s about 7 feet tall and 400 pounds of muscle, capable of shrugging off bullets. She’s also a sweety, both gentle and polite, and comes off as incredibly socially awkward when she speaks (in sign language due to her tongue being cut out).
I also rolled randomly to see what her mental stats are (it’s a ttrpg derived fic and she was a minor character intended to be important for like one arc). She rolled near maximum for intelligence, wisdom, and charisma.
She was so cute and sympathetic to my readers that I decided to keep her around, and had a thought. What would a socially stunted genius with the physical strength necessary to overpower 99.9% of people easily do for someone she platonically loves? Eliminate problems for him.
She’s been systematically murdering people that are legitimately dangerous antagonists for my MC that he was not inclined to kill for various (mostly “modern person who isn’t a psychopath”) reasons, because she doesn’t see why he didn’t and assumed it was for PR reasons. It took him forever to realize because he had the same blind spot as my readers. Cute personality, needs hug, needs help -> infantalize.
She’s still not a main character but she’s gotten several POV chapters at this point and is firmly in B tier, with the current arc’s b plot revolving around her to some degree.