Peasant Woman’s Decreed Life as a Wife - Chapter 942 - : Discovered

After rebirth, she, who used to be a top international spy, becomes the eldest daughter of the Fengs, a fat girl who is ugly and foolish in the eyes of the ordinary people.
Mastering Royal 18 Saber Moves and Purgatory 9 Palms, she rose to fame with the martial arts of Demon Cook.
Upon an imperial edict, she was ennobled as the wife of Lord Cen, and then suffered various intrigues and plots…
She proved herself to be a real overmatch and a true genius to the world…

Luo Zheng is at the bottom of the Luo Clan hierarchy, despite his family being the founders of a power refining technique that could instantly defeat any opponent.

One night, enraged by unfair treatment from a family steward, Luo Zheng burns the family records. In doing so, the hidden magic in the book engulfs him and Luo Zheng becomes a new skilled fighter. Fleeing his home and despicable clan, Luo Zheng must learn to harness his powers to rescue his younger sister while his own cousins are on his pursuit.

- Description from Novelupdates

Nie AnAn woke up one day and realized that she had transmigrated as the villain’s adoptive sister.

In the novel, the villain conquered left and right, and his always woe-is-me younger sister was always cleaning up after him. The two of them were rightfully the grim reapers in the book.

The very next day after her transmigration, the soft and delicious Nie AnAn passed out from seeing blood.

And so —

The shivering competitors noticed that their nemesis’s sister had turned to a delicious treat — and wanted to protect her;

The original male lead noticed that young Miss Nie, who had been chasing after him this entire time, wouldn’t even give him the time of day anymore — and felt unbalanced;

Young Master Nie was very happy that his parents had two kids back then– she was so GD cute;

A certain cold blooded and violent villain had been going home earlier and earlier, and the way he talked was becoming gentler and gentler.

Villain Brother: AnAn, come over. Let me try some of it.
Nie AnAn: Hold on, gege. It’s not ready yet.

- Description from Novelupdates

There was a Senior Brother and a Junior Sister. One of them was transmigrated to this world and had cheats while the other was the reincarnation of a Great Emperor.