You are Alice Takanashi, alias Void Heart.
And you used to be a magical girl.
The advent of the magical girl coincided with the rise of arcologies like Terminus City. The wake of the Resource Wars left the world in chaos and anarchy. Nations balkanized, refugees fled to distant countries, and all kinds of supernatural nasties came crawling out of the woodwork to openly feed on the fragmented, warring tribes of humanity.
Naturally, magical girls rose up to combat those supernatural nasties. Given arcane power by forming Pacts with fluffy alien beings known as Contractors, these girls set out to defend hope, love, and all that's pure and good in this ailing world.
That's who you used to be. You're much… Different now.
These days, you are the very model of a sensual succubus. Hauntingly attractive, indecently so to be perfectly frank. Your flawless skin, your perfect facial structure, the lewd glow in your eyes and the lurid womb tattoo proudly emblazoned above your pubic mound… You ooze sex appeal with each sultry sway of your hips, and you damn well know it.
Being evil's never looked this good. Or felt this good. You certainly didn't look this good when you were just another magical girl, futilely fighting for a broken, fragmented world. You certainly didn't feel as happy as you do now, revelling in wanton debauchery and hedonism…
It's just a pity you don't have any steady partners to engage in debauchery with. Or to debauch and utterly corrupt, just as you've been utterly corrupted. Humans break so easily, and what's worse is that they tend to stay broken. Your regular magical girl's not much better.
You'd entertain yourself with some toys or pets, but you don't actually have those right now.
It has to do with why you came to Terminus City in the first place.
Terminus City was established towards the end of the Resource Wars to solve the rampant refugee crisis and overcrowding epidemic. It started off as a set of glorified slums that blossomed over time into a regular metropolis, an ordinary place where refugees, immigrants, and other hopefuls flocked to in order to start again.
A regular cesspool, a hive of scum and villainy. A fertile breeding ground for all kind of supernatural chicanery to pop up in the shadows of human activity.
And where supernatural creatures lurk, magical girls patrol. And in a hive as wretched as Terminus City is, any magical girl who patrols regularly in this city has to be the best of the best, tough as nails to the point of international renown.
You've just spent hours reviewing covert footage of these magical girls in action, you know damn well their reputation is well-earned.
And so, you've come to this city yourself, a wandering maiden in love like so many other wanderers who come to this city.
And you are in love. It was love at first sight when you laid eyes on the magical girls of Terminus City. Such high hopes you have for them. The potential they possess. So pure, powerful… Beautiful. But they could be made more beautiful. You don't want just to debauch these girls; you want to utterly corrupt them. You want to push them off the edge of sanity, lure them into the loving embrace of darkness…
Ideally, they'd end up living with you in a blissful life filled with decadence, where you'd dote on and be doted upon by cute, lewd girls, but you're getting a bit ahead of yourself now.
Corruption's not something you can just jump right into. There's a process to proper villainy, and careful preparation that you must go through to properly corrupt these magical girls. A misstep at any point could lead to… Complications.
It's part of why you didn't bring your toys and pets with you when you moved to this shitty excuse for a proper villainess' lair. The magical girls of Terminus City are veterans, they've been stomping demonic hordes and eldritch abominations to the curb for years at this point.
As much fun as it'd be to engage one of them in battle, to be able to feel their luscious flesh against your own, to take in their scent, engage in banter…
Well, there's no sense in making your own goals that much harder to achieve. So you're flying under the radar now. Hence, holing up in an abandoned hospital. It's much less obvious to build your own lair from the ground up instead of having everything shipped in all at once. Less chance of any interlopers getting in the way too.
All your preparations and machinations have paid off in that you now have time to think and plan…
Plan on how you're going to corrupt your first target.
Luminous Libromancer is commonly known as Terminus City's Silent Mage. The Mistress of Mystical Arts, capable of casting ten thousand spells and cantrips. Her sheer magical genius is only surpassed by how aloof she is. She's made zero public appearances, had no interviews. She's famous for how elusive and mysterious she is. As far as you can tell, when she's off the clock, she spends all day holed up in her tower, Libromancer's Libram.
Her isolation makes her the perfect first target to tailor and fine-tune your corruptive methods. Her teammates are less likely to notice anything's wrong until it's too late due to how aloof she usually is, which'll let you fly under the radar that much longer…
The only problem is actually managing to track Luminous Libromancer down.