Lately I've been on a villainess kick. I would prefer no harem or reverse harem. A story like A self proclaimed villainess' fiancée's observation log or I Don’t Want to Become a Villainess, So I Aim at Becoming a Perfect Lady Together with the Prince! where though they have their memories a) it's told from a different perspective or b) They remain themselves just with aditional knowledge PS bonus points if they have an existential crisis over whether they are themselves or their past life. Thank you!
Welcome to the brotherhood, explore to your heart's content. https://www.novelupdates.com/stag/villainess-noble-girls/?st=1&col=1,2,3,4&sort=trank&order=asc God, I looked at these and I realised I've basically read them all.
Albert Ke no Reijou wa Botsuraku wo go Shomou desu is a funny one where she is trying to keep up with her Villainess role Doomed to be Cannon Fodder - I like this one but I dont know if it meets your mark as she becomes the Villain character in the novel she reads who is going to end up dead so she tries to struggle not to become Heroine cannon fodder.
There's two novel's I'm translating that you might like, a little different, but has similar feels to it I Refuse to be a Supporting Character The CEO's Villainess Childhood Friend My sister's also translating a KR novel I asked her to do called The Male Lead's Villainess Fiancé hope this helps xD
Highly recommend: Kenkyo, Kenjitsu o Motto ni Ikite Orimasu XD Lololol I Reincarnated into an Otome Game as a Villainess With Only Destruction Flags… (reverse harem) An Otome Game’s Burikko Villainess Turned into a Magic Otaku (1v1 sweet~) Common Sense of a Duke’s Daughter (political~) It Seems Like I Got Reincarnated Into The World of a Yandere Otome Game (everyone's a yandere) I Decided to Not Compete and Quietly Create Dolls Instead (cute XD)
Haunted Duke’s Daughter - The villainess remains herself, but has a reincarnated(?) person's voice in her head. I Am Troubled That My Fiance Is a Villain - The title pretty much explains this, but this one is actually the reverse; the villain is the reincarnated girl's fiancee. There is a villainess too. (Not sure if this is included in what you're interested in) I Play the Role of (Villain/Heroine) in a Japanese-style Otome Game - This one is actually only told from the Reincarnator/villainess perspective for the first few chapters, after that it's from the perspective of the non-Reincarnator/heroine