The Regressed Son of a Duke is an Assassin
ML is youngest bastard son of noble "guardian" family. Raised as eldest sons "shadow" (assassin/dirty work). Betrayed and killed by brother once his goal was achieved. Regressed to childhood, future knowledge and skills from past life. Becomes OP "shadow/mist assassin". Getting revenge and foiling eldest sons schemes.
I Became the Male Lead’s Adopted Daughter
FL is reincarnated as adopted daughter (actually his lost neice) of OP "beast" duke from novel. Dukes family fighting corrupt nobles/emperor. Most of the story so far has been relationship development between FL and other characters.
Death Is The Only Ending For The Villainess
FL reincarnated as "villianess" of dating game on hard mode. Adopted daughter of duke whos bio-daughter disappeared. Family treats her like garbage. Can use skills only thru quest screen. Has to reach 100% love meter to avoid death ending before missing girl returns. Real daughter is part of a weird cult and can use mind control. At FL's coming of age ceremony tries to frame her for poisoning but FL knows and drinks it instead.
A Stepmother's Märchen
Young FL is married to dying duke to be temporary head until son comes of age. Hated by children and turns into "iron lady". Killed by churches scheme on eldest sons wedding day. Wakes up in the past on day of husband's funeral. Beacomes close to children in this life and uses future knowledge to beat schemes of other nobility &church. Currently fighting against corrupt church who wants to use family's influence for themselves.
The Viridescent Crown
FL gets reincarnated into novel as ML's villainess stepsister who was supposed to die as a child. Uses future knowledge to stop ML from getting abused and temporarily inherits duchy to stop it from being destroyed. When ML becomes adult, he inherits duchy and proposes to FL. She is standoffish bc the "main character from another world" was originally his lover and will be coming soon.
To Those Who Long for My Destruction
FL can travel between time/space. Returns to 10 yr old self to get revenge on everyone who wronged her. Scum father, and emperor/royal family. Uses future knowledge to overcome schemes and gain influence/power.
My Body Has Been Possessed By Someone
FL is abused by family and treated as cursed by everyone for resemblance to "black fog" disaster/disease. Gets body swapped w Korean girl for 12yrs. After becoming a holistic(herbal) doctor, they swap back. Uses medical knowledge to create weapons to protect herself and cure others "unknown" diseases.
Baby Tyrant
FL reincarnated as baby princess in fantasy world. In previous life, was abused/neglected so in this life she pushed away family to not get hurt again. Prophecy that she is "seed of god to save the world" and has ability to speak with animals/use holy power. Plots from other countries/nobles to gain power. Father makes her empress as a baby and he's regent so no other country could harm her.
Turning a Crazy Dog Into a Young Master