MTL - Great Voyage: Invincible From the Era of Rocks - Chapter 397

Perhaps it is the choice of fate. As a senior otaku, Qian Lingfeng got the “steel shell system”. However, when he swept the world with the system, became a local rich man, made all kinds of beautiful women, opened a harem, and realized the ultimate fantasy of thousands of otaku, he found that things seemed far from simple!
When the end comes, biochemical zombies suddenly come down, fierce beasts are in power, bloodthirsty zerg roam to kill the world, and human lives are comparable to dirt. Where will weak human beings go in this world? Is humanity going to be extinct? Or … can an otaku save the fate of the human race?

- Description from Novelupdates

Mason was a mercenary, until the day he died on a mission after being betrayed by his unit.

Garou woke up in the world of Naruto, reborn as an ordinary civilian of the Hidden Leaf Village.To his shock, he discovered he suffered from the same limitation as Rock Lee: completely talentless in both ninjutsu and genjutsu. Worse yet, he belonged to the same generation as Naruto and the other members of the Konoha 12.But Garou wasn’t the type to quit. He knew that pure grind beats natural talent.Might Guy had already proven that much.However, unlike Guy, Garou had seen the end. He had watched the anime.He understood that taijutsu, as powerful as it was, always burned out like a firework, brilliant but brief.And this time, he had no intention of going out like that.Determined to break past the limits, Garou began creating his own techniques, pushing the boundaries of what a “mere” civilian could achieve.And the mysterious light orb in his mind granted him powers based on the influence his techniques had on others and the world itself.The world of Naruto would never be the same again.The grind doesn’t stop until the world bows before his fists.

After transmigrating, Chen Yu found himself in a highly militarized world. But the “will of the world” had concluded that he was an intruder and put a curse on him.