Isekai Maou to Shoukan Shoujo Dorei Majutsu - Volume 7 Chapter 3 part5

She, a modern hidden ghost leader of an organization which gathered insane prodigies proficient in the various differing skill-sets. Highly skilled in medicine and poison, executes covert assassinations, viewed as insane and demonic in the eyes of people of the world. Killed in an accident, and reborn into the body of a disfigured young girl.

What? Face disfigured, identity stolen? A return to the family dim and hopeless? Her identity can be given up, her family can be forgone, but as for the one who harmed her predecessor who inhabited this same body, if she didn’t at least make them scream in unimaginable agony and throw them into a state of wretchedness, how could she live up to her demonic reputation? Endless turmoil ensues and it’s a battle to dominate over all! See how she shook the world dressed in a suit of red, her sword up against the dominant powers that rocked the Heavens! Her name spread across the seas, shocking the earth!

- Description from Novelupdates

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----

Overnight, Tangning became a big slave owner in the southern United States with three large plantations and hundreds of black slaves who could be driven at will.

Tangning was very satisfied with the result of such a time-travel, but then he sadly discovered that he could only enjoy three years of such a good life, because three years later would be the “Civil War”, what should he do after this?

- Description from novelbuddy

A fluffy, sweet modern GL story about a mature older women and a cute university student.