Tenebroum - Chapter 4: Gazing into the Abyss

Liola—the best assassin in his world—has vowed to kill no more. He was being chased by an assassination organization when he accidentally dropped into a parallel universe: through a dimensional gate and into poor teenager Kaiser’s apartment. Instead of going to the government shelter for lost dimensional travelers, Liola and Kaiser wind up going to school together.

Liola has been trying his best to live the life of an ordinary person, but after certain things happen one after the other, he begins to realize that being an ordinary person could be harder than being an assassin.

A teenager finds himself in the Marvel World with the Dragon Balls, and has to find a way to survive!

Shenron: “Say your wish! Any wish can be granted, but you only get one…”

Teenager: “Any wish could be granted?”

Shenron: “Of course!”

“Great!”

Teenager: “Shenron, please get me out of the Marvel World; return me to my original world!”

Shenron: “I’m sorry, I can’t do that…”

“….”

Teenager: “What? What were you bragging about then, saying you can grant any wish?”

Shenron: “Your body is from this world, therefore….”

“….”

Teenager: “Okay, then give me the power of a Super Saiyan! I want be able to beat Thor and Hulk, surpass Captain America and Iron Man!”

Shenron: “I’m sorry, I can’t do that…”

Teenager: “Worthless dragon! What can you do?”

Shenron: “I can…”

- Description from Novelupdates

Felix's life on Earth had become a series of dead-end jobs, ruined relationships, and rotating apartments smaller than most postage stamps. By all accounts, even his own, he was a coward. Too afraid to move forward, to take risks. Yet when given the chance to choose between risking his life or walking away from a deadly encounter, he didn't hesitate.Moments before his untimely demise, Felix was snatched from earth and thrust into a magical world known only as ‘The Continent’. Empowered by the ‘System,' he learns that he can strengthen himself through combat and dedication. To survive he'll have to push himself beyond his limits, or else fall to the monsters all around him.Levels, stats, and magic. Death is the start of a terrible fate, but if he lives…who knows what he will become.

Shi Jin once read a book. It was supposed to be about satisfying the desire for vengeance.