I dont read this series but....
WTF is THIS???
Dio's unofficial daughter who is cursed by her quirk to be literally "blood thirsty" and thirsty in ever sense of the word. It's a play on vampirism by Hori where victims of vampires can be infatuated with their vampiric predators and thus become their willing/subservient "ghouls".
Toreador vampires in the Vampire: The Masquerade series can become extremely infatuated with anything they find beautiful and this can be literally anything too as far I remember but also tends to be especially artistic and typically beautiful things ofc. They can be transfixed with for eternia even, or at least decades, centuries or so, going into "Torpor" or "vampire comas" basically.
Toga's quirk makes her dependent on feeding on other's blood like vampires but she also develops severe infatuations or obsessions with them under the guise of romantic love and even lust ofc. An absolute spin on "bloodlust" even.
She was regarded as a freak by MHA society due to her quirk and how it forces her to behave. Like carnal instincts you cannot control/supress by yourself at least?
She's definitely intentionally inspired by DIO of Jojo but also vampires and yanderes/hormonal schoolgirls ofc.
This "morbidly romantic" song comes to mind with her and her circumstances too:
My example of what people like this would say/think/feel in regards to beautiful people and things that they obsess with:
"If I can't have you then nobody can or will. We will be together forever even and especially in death! I will preserve your beauty forever!"
It's kinda like Mr Freeze and his wife Nora too, especially the darker takes on him too. Love truly makes us "crazy"! "Crazy in love".
Toga's quirk lets her transform identically into the person she drinks the blood of and the more blood she gets of theirs, the longer the transformation. Later on, she awakened/evolved her quirk to replicate their quirks too which she used to a satisfyingly brutal effect with Uraraka's quirk too.
As you can tell, I really adore characters like Toga and vampires too lol. I'm not an actual fan of blood sucking nor yanderes but there's something relatable, something I find sympathethic (simp-pathethic) about them. There's a morbidly beautiful tragedy in situations like hers, Twice's and Dabi's for example. I love characters and villains like this. Vampire the Masquerade: Bloodlines, one of my favourite games of all time really explores these kids of concepts too and I love it.
I don't actually condone the stuff I talk about here too ofc, I'm fascinated by psychology/human behaviours and why we do the things we do. Toxic, dark romances also are immensely popular with women especially as we saw with 50 Shades of Grey, Twilight and similar stuff.
You also get women writing love letters to and obsessing with, falling in love with serial killers, rapists, psychopaths in general and such, wanting to marry them, even if they are on death row and patiently waiting months or years to hear from or even to see or meet them. It's pure insanity. Guys do this too ofc, especially with the Yandere girl fetish that is immensely and disturbingly popular in the anime/manga community ofc.
I think there is a plethora of mascohism amongst other issues going on with people like this. It's not healthy at all and even gets a lot of people killed. Not to mention people who literally simp for actual terrorists, killers, cult leaders etc IRL like the Batman theatre shooter, Boston Bomber, school shooters like Elliott Rogers and especially infamous criminals and thus killers out there like Ted Bundy, Charles Manson, Jeremy Meeks.
People will justify anything as long as they find the perpetrators attractive, honestly. It's one of the most rawest, brutal and thus black pilling things I've seen in the world. But I think back to how people used love watching public executions, witch burnings, actual gladiators fighting to the death, brutal murders of slaves and prisoners and so on. It's actually one of the biggest reasons why I hate history so much.
Apologies for how morbid this discussion got lol but MHA depicts and talks about lot of very dark topics like OP does.