Warlock of War: My Ares System - Chapter 2 System?

The two faced number one female spy transmigrates to a different world and becomes an outrageous idiot girl. When she woke up, what she had to face was consecutive blows of the decline of her family clan, her crippled martial skills, and her disfiguration. To protect her family, she must obtain the treasured book, obtain outstanding achievements, summon a dark beast army. Wait and see how in this unfamiliar, dark magical continent, she dies and becomes a demon then steps up to the top, making all of the formidable people in the world bow down to her in respect.

- Description from Novelupdates

Long Chen, a crippled youth who cannot cultivate, is constantly targeted and bullied by his fellow noble heirs. After a particularly vicious beating, he wakes up and realizes a Pill God’s soul has somehow merged with him, giving him some additional memories. Within those memories is the mysterious Nine Star Hegemon Body Art, a cultivation technique that even he can train in, but whose secrets and origin are still a mystery to him. Relying on his improved instincts as he finally begins to cultivate, he realizes a huge conspiracy is underfoot within the Phoenix Cry Empire, one involving his father, members of the imperial family, and even the Emperor himself.

Yu Linglong is the shu (born of a concubine) daughter in a general’s family. Since her mother was only a tribute dancer, her position is the lowest of the low. She used to live with her mother outside the father’s residence, and they only received some monthly money from him. He didn’t bother seeing them. But when her mother dies, she moves into the general’s residence.

The general is a very irresponsible and violent man. He doesn’t really get attached to women, just letting his lust dictate his actions. His wife is a jealous woman, who killed one of his previous concubines, because he doted on her too much. She similarly wants to get rid of Yu Linglong, in part to vent her frustrations over her husband’s cheating habits.

Because the sixth miss – the general’s legitimate daughter, was bitten by a snake, she needs detoxification. The cure was apparently getting poisoned by scorpions, to fight one poison with another. But since she’s already weak, they decided it would be better if she drank the blood of someone poisoned by scorpions instead. The general’s madam naturally decided to use Yu Linglong’s blood. During the process of getting bitten by the scorpion, the original timid Yu Linglong died of fright (and maybe poison? it’s never made clear). Then Yu Mei takes over her body.

Yu Mei is a modern woman. She was some mafia boss, so she’s very capable with fighting and overbearing attitude. She died because the man she fell in love with betrayed her and killed her. So she doesn’t trust easily afterward.

Since she took over Yu Linglong’s body, she refuses to adapt to the circumstances of a lowly illegitimate daughter, and uses her violence to fight for a peaceful life, where no one will challenge her and plot against her. Basically, she beats them up into submission. In the meantime, she acquires a tail – a very persistent prince, who only seems to stick to her harder, the colder she treats him. Did ancient men have such heavy tastes, she wonders.

- Description from Novelupdates

Reincarnated into a land of cultivation, Yuan Zhou uses his Earth knowledge and assumptions to become a genius under the heavens for both business and cultivation. However, he walks the path of defiance, exceeding all rational cultivation bounds. His business ideas struggle against the stagnant culture that pervades the land, but the things he doesn't lack are his drive for immortality and power.