Elf Tensei Kara no Cheat Kenkoku-ki - Chapter 19Book 1: -3: Battle

“From today onward, you’ll take your brother’s place and take over the inheritance of the Gu family!” With her mother’s declaration, she became her twin brother’s substitute.

Dressed as a man, but unwittingly enticed a lot of sisters!

Incidentally, she also captivated the younger sister of the most powerful authority in China, shouting to marry her!

Ming Shao was furious: “From now on, you will follow me. I will train you to be a qualified brother-in-law!”

Since then, she eats with Ming Shao during the day and lives with Ming Shao at night.

She has always thought that Ming Shao treats her as a prospect brother-in-law, but one day, Ming Shao pushed her down the bed and plundered her mouth!

Hey! Didn’t he say he wants her to be his brother-in-law, how come he turned into her boyfriend?

- Description from Novelupdates

Eli was transmigrated to a world of magic and became immortal.

He had endless life and could never die.

“Huh? I’m talentless? Then, I’ll just train for as long as I need, even if it takes 1000 years. That should be enough for me to become strong.”

“The skill is hard to learn? Then, I’ll take a few dozens of years to research it. There’s no way it’s that hard, right?”

“What? I can sacrifice my life force to gain spirit power? That’s a bargain!”

“The enemy is here? Hell, I’ll just hide for 10000 years. Let’s see if he can outlive me. I’ll come out once he’s dead.”

This is the story of an immortal who first struggled to live in the world of magic until he became strong enough to slaughter endless worlds.

Gu Changge, a noble lady from a wealthy family, is a well-known business legend in Yuncheng, going into business at 15, taking over as President of Gu Group at 18 and becoming Chairman of the family business at 30.
She is murdered by her husband Shao Tianze, just to give his mistress Gu Changle a healthy heart. But a premeditated car accident makes Gu Changge revive in a new guise and settle into an 18-year-old girl, Song Yunxuan.
The new face, young body and experienced soul become her weapons of revenge. In her struggle with the four big families in Yuncheng, can Gu Changge shrink back? Will she open her broken heart again? Can she always head off dangers in power struggles?
Let’s find out if Gu Changge can revenge herself and create glory again.

- Description from Novelupdates

In the original lines of the novel, I was a villainess—used as a political tool by my father and older brother—who ended up dying at the hands of my future husband.