MTL - Marvel’s Hogwarts Wizard - Chapter 22 Iron Man's Gift

The old man pointed to the flower-like woman and said, “Call her mother from now on.” He then pointed to a flower-bud-like girl and said, “This is your sister.”

My younger sister was not cute.

She was arrogant, taciturn and weird, but she knew how to please our parents.

She was two-faced and deceitful, but it seemed like she only treated me that way.

I cared for her, tried to please her as much as I can, but she still disliked me.

Until one day, I found out her secret, our relationship began to get a little bit weird…

- Description from Novelupdates

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

An alien race invaded the Earth on June 6, 2128. At the midst of this war, many nations allied with the alien threat and the war nearly wiped out the rebelling humans of the planet. At the edge of mankind's survival, the United Nations Army launched its forces to eliminate the immediate stellar threats that loomed over Earth.

General Seeker Carlean, commander and leader of the mission, risked and gave his life to destroy the immediate stellar threat. The battle was won though Earth lay in ruins. Perhaps mankind will live to see a few years of peace before the alien threat returns to wipe out their existence.

At the immediate aftermath of the stellar battle, the fallen Seeker Carlean awakens and finds himself at aged 17, living the peaceful life he lived 16 years before he died.

So begins a new game in the battle for humanity's survival.