Suterareta Yuusha no Eiyuutan - Story 3-7:『Frivolous Person』

The Supernatural era descended, the rules changed, mystery arrived, and the world altered. Countless ruins of civilization emerged, and an abundance of Heavenly Materials and Earthly Treasures lay at everyone’s fingertips. Radical faction, “This is the best of times, entering a new world, excavating relics, mass evolution!” Conservative, “This is the worst of times, with countless monsters outside, once you leave the Safe Zone, extinction awaits humanity!” … Meanwhile, at a remote ruin, Lu Yuan successfully discovered new treasures and sought after the mysterious wealth, desperately trying to contact his fellow Earthlings. “Found a communicator, can it get through?” “Hey, humans—I’m almost becoming a god, and you’re still hiding in the Safe Zone?”

Crossing into the world of Naruto, and acquiring the One Piece system, with all the powers of the world of One Piece, swordsmanship, devil fruit, domineering.

-Do you think that your fire is very powerful? I have the burning fruit.

-Do you think that your thunder is very powerful? I have a thundering fruit.

-Do you think that your otter is very powerful? I have the frozen fruit.

-Did you said you want to die? Don’t worry, I also have a nickname: Death Doctor.

- Description from Novelupdates

Step into a world where science meets the unknown, where mechas clash in brutal duels, and where every Biocore holds a mystery waiting to be unraveled.Follow Nioh, a genius weapons designer, as he uncovers lost technology, battles biomechanical titans, and pushes the limits of power, in an intergalactic thrilling adventure

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.