Toaru Majutsu no Index: New Testament - Volume 7, Chapter 1: Altar of the Wisdom King. Foreign_matter.

Bored in class, Ivaim suddenly transmigrates into a world plagued with Fractured Realities.A century ago, Reality Masters suddenly arrived— bringing a wave of terror over the planet.Just as the people despaired, they began to discover “Threshold Items” which allowed them to enter the domains of these Reality Masters.They had two options starting from there :One, to become a Reality Walker— a person marked and blessed by a Reality Master, fighting by their side in order to defend against other Reality Masters.Or to become a Reality Ruiner— A person who kills Reality Masters, directly consuming and taking over the powers that they posses!However, to Ivaim, he seemed to have taken on a different path.As he looked towards his own body, he sighed as he realized that he was neither a Reality Walker, nor a Reality Ruiner.—He had somehow become a Reality Master....

[You can now choose three of the following seven options
1. Go back to five years ago with the present memory
2. Five centimeters taller
3. Seven million deposits
4. Appearance +50 points
5. A company with a market capitalization of 500 million
6. Proficient in a foreign language
7. Teaser live broadcast 10 million virtual coins]

Li Ang became angry after finishing the selection: choose every day, choose, choose, you will give it after the selection!
…
Fuck, it’s really shipped!

- Description from novelbuddy

Living in this apocalyptic world full of zombies and monsters, the rich rely on technology and the poor rely on mutation.

Shen Shanwu, 13 years old in appearance but 31 years old in reality, is a mutant that can alter his own appearance. Although he looks like a child on the outside, his wisdom is not very good. One day, he was just passing by when he was suddenly forcibly adopted by a major general, whom he didn’t know where he came from.

He resisted, but when he looked up, it turned out to be an old acquaintance.

The little boy, who could only hide behind him and cry, transformed into the unsmiling, cold, and tough man in front of him. And that expression of seeing a dead beloved is really unsightly…

Shen Shanwu: Can you smile?

Jing Huan: After Shanwu died, I couldn’t smile anymore.

Shen Shanwu: …Who? Who do you think is dead?

It took a long time before he found out about it. He found Jiang Huan crying and holding Shen Shanwu’s nameplate in the middle of the night and told his adopted son how good Shen Shanwu was… All of this…was seen by Shen Shanwu himself!

Jiang Huan (raising his gun): Since you have seen my embarrassing side, then I can only marry you or kill you.

Shen Shanwu: …

Shen Shanwu: Marry, marry, marry! I will recruit 800 zombies to carry you home!

- Description from Novelupdates

“Now you see?” she shouted in a mix of annoyance and disappointment. “You can't outsmart Scrients! They're the most intelligent beings across the two realms.”“You're right,” I muttered, averting my gaze with a heavy sigh. “I made a mistake. I was too arrogant to think that a mere human like me could fool them.”—BOOM!!“Heik! Wh-What was that?”“Hmm? I'm not sure. Maybe you should go and ask the most intelligent beings across the two realms. Oh wait, you can't. I killed them all.”______My name is Samael Kaizer Theosbane.On the last day of high school, I got into a fight with a kid I used to bully.It was a stupid, pointless scuffle, and in the middle of it, I tripped and hit my head on a rock.That’s when the memories came flooding in - the memories of another life, of a different world.Suddenly, everything made a twisted kind of sense. I realized two things.First, I was in a game I used to play in my past life.Second, I was a villain. A villain!Not the cool and mysterious kind, either.No, my destiny was to be manipulated and die a dog's death!I was the worst type of cliché: an ungrateful, privileged, insufferable young master. The sort you'd find in those poorly written fantasy stories.The kind everyone hates — a snobby brat from a powerful noble family who thinks he owns the world just because he was born with a silver spoon lodged in his mouth.You know the type. The one the hero beats to a pulp to prove his worth.Yeah, I was that guy.And the hero? The hero was the kid I’d been bullying all this time. The same one I got into a fight with.He was the supposed savior of this damned world.A world teetering on the edge of destruction, beset by wars, calamities, and a grim future that only I knew.And at the end of it all, the final antagonist of the game, the undefeatable boss… the Spirit King, was waiting.But could I even make it to the end?Could I conquer a game where defeat was the only certainty?A game that was now my reality!“Ah, fuck it.”I had no idea if I could, but I sure as hell was going to try.Extorting extras, manipulating main characters, twisting the story to my advantage, stealing the hero’s cheat items, killing villains before they could become threats - nothing was beneath me.Would the main characters be affected? Who cares!Would the story change? Even better!All I cared about was me—my survival, my life, my choices.“I will live this life with no regrets.”…But as I soon discovered, fate was not easily changed.And the price of altering one's destiny was steep.