So in my story my MC's love interest is his servant she became his servant by making a deal with him and she became a supernatural being that acts as his personal hunting/attack/guard dog for lack of a better term. I'm not sure how much if any impact her powers should have on her personality. I originally wanted them to sort of reflect her personality to a degree. Basically all her life she's been controlled and used and she's always craved power and respect. The problem is that she's not respected because she's viewed as an object by men and other women see her as this woman who dresses and acts provocatively and view her as a whore. She acts this way because she is a former beauty queen whose parents constantly drilled into her that her looks were more important than her brain (basically she's very smart woman it's pointed out she was more than likely a child prodigy) however her life went down hill her parents disowned her and she was sucked into the world of human traficking. Long story short she meets a demon he offers her power in exchange for becoming his personal servant. She agrees to it because it's too good an offer on paper and shes loyal to him because he's the first person to recognize her intellect. She's like a fury, siren, and succubus combined and is able to control men-and sometimes women- and get them to do what she wants however she can also torment a person and drive them insane. Now this is the part I find confusing she's a bit of a contradiction in that she's very sexual and at the same time self conscious about it. I guess she wants to be both respected and wanted. She doesn't like her powers because she feels they represent how people lust over her(even though its like a reflection of both sides) however she enjoys using them and another problem I have is selling that she grew to enjoy hurting people. I don't know if it makes more sense to have her powers cause her to have a sadistic streak or for her to have a sadistic streak already and for her powers to just highlight that part of her personality.
Perhaps she's grown to like pleasing the demon, so her sexual acts and violence against others are no more than bids for his attention? She knows what she does is wrong and she is self-conscious about her actions, but she forgets all about it when he treats her like an intelligent equal and praises her abilities?
If you ask me, it's more powerful if the powers that a certain character acquires further aggravate that same character's thoughts and personalities. For a character to be implanted within a story and arrive with a set, unchanging personality and then for him/her/whatever to be gifted supernatural powers and not have their own mindset change, just doesn't do it for me. Do you understand me? Sucked into the world of human trafficking for you know how long, she's definitely going to come out differently, so when given appreciation and acknowledgement when no one else has done so, she could very well accept any offer to shed her former image and gain a new one. And when she crosses that line, she can choose to abandon all human aspects of herself or keep what little resembles her former self. After having read your post several times, I feel pity for this character. She's grown up most of her life as an object and nothing more than an object. Went to Hell and back. So when given the option, she vents her rage onto unsuspecting people or maybe the very ones who led her to where she is now. With all the turmoil inside her now, being used like meat, it makes sense for her to search lustfully or genuinely for love. What's your character's name?
She tends to go by Pretty Poison (mostly just Poison) she does this because her "stage name" as a sex worker was this and she mostly participated in acts BDSM and while working she started killing clients regardless of their gender that's a thing with her she has no compassion for anyone regardless of whether they are a man or woman. The reason she has done away with her original name is she just escaped into her dominatrix persona and purposefully erased any "good" emotions. Another thing that's interesting about her is she hates women more than men which has to do with the fact that another woman was in charge of the sex traficking ring and her mother constantly body shamed and verbally abused her as a child. She basically does not human beings at all she thinks men are mindless barbarians and she thinks women are mindless crows who constantly flock to shiny objects she's a full on nihilistic misanthropist. She's highly unstable so much so she refers to her past self as if she was different person to the point where she claims she killed her past self which is why her real name and identity is such a shocking and confusing reveal.
Maybe she tries to tell herself that she isn't sexual, she's just pretending to be? If I was writing this, I would say that "Using dark magic will supernaturally compel you to become violent" is a lie that she's been telling herself for so long that it retroactively might as well have become the truth. Have you ever read the Dungeons&Dragons webcomic The Order of the Stick?