Toaru Majutsu no Index: Genesis Testament - Volume 4, Chapter 4: Beyond the Two Choices – Duel_Against_R∴C∴O∴(for_Save_Mother).

Xiao Rou, a girl growing up in a poor countryside family, finds that she’s actually the daughter of a wealthy couple. Her mother had mistaken another girl for her back at the hospital. Thinking she would change from an ugly duckling to a noble swan and live happily ever after with her real family, reality strikes her in the face.

The other girl, Xiao Jinning, who had taken her family, her fiancé and everything else from her, uses every mean possible to frame her up, so when she returns to her biological parents, she finds her parents despising her while still doting on Xiao Jinning. Framed as a thief, she is expelled from the family and as soon as she walks out the door, she gets hit by a car and her spirit dies a miserable death thanks to Xiao Jinning.

Meanwhile, Tang Xi, a real princess, the heiress of the powerful Empire Group, is murdered by her greedy relatives. When she opens her eyes again, she finds herself in another girl’s body. She has become Xiao Rou and has a magic system—008 in her body! With the help of 008, she begins her journey for revenge. She would avenge poor Xiao Rou, punish her murderers, become the most famous star, and… make up with her true love—Qiao Liang.

- Description from Novelupdates

What happens when you survive seven hellish years on an alien planet in the ultimate battle of the strongest in the universe—as a human?What happens when you give everything you have and more to defeat the final boss in a battle to the death… only to wake up the next second, back at day one?Going through it all over again?But something is wrong.The game in his hands isn’t Nyxfall 6: Dark End, the world he spent over seven years surviving. It’s Nyxfall 7: The Veilbreakers—the next installment.He won? So now he’s been given another game to play?And he’s not alone. There are others like him in every alien civilization. This time, it’s not just survival—it’s about who can lead their people best.That is… if they even care about their people at all.Why bother leading at all? With everything they have learned, why not exploit the system, amass unimaginable wealth, and live like a king in a game that pays in real money?

During the demon-summoning ceremony, Aiwass finally recalled his past life's memories.This should be an online game that his family's company had released and operated for six years. Now, his foster father was the leader of the latest version's antagonist organization.He would expose his identity six years later, hesitate and then defect from the protagonist's side. Ultimately, because he decided to take a fatal strike meant for the player character, he was killed by his upright older brother in a transitional CG without even a chance to enter the main content.——But the problem was not too significant. Aiwass also knew many secret advancement routes exclusive to the player character, as well as the Nurturing Secret Sequel regulations of the various Paths. He believed he could reverse his unfortunate fate……So now there was only one issue left.“According to the original plot, shouldn't I have been rescued by the protagonist before this lousy ceremony even began?”Tied to the ceremonial altar as a sacrifice, Aiwass fell into contemplation.

The boy who Sneaks in My Bedroom Window