Saving the World in an Apocalypse-Style Text Game - Chapter 244 - 167 The Ten Monsters Slaughter the Tyrant

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

Sam Sanderson is envied by many for his job, however he himself didn't seem to like it much.

Due to his expertise in nanotechnology he was tasked with monitoring the state the Valkyries, humanity's strongest weapons who all just happen to be made into gorgeous females.

Forbidden from even touching any of them, Sam spends his days in agony watching flowers he couldn't hope to touch. However one day all of that seemed to change.

The NPC sets out on a journey to defeat the Demon Lord, joined by beautiful girls he meets along the way.---This is an NSFW story, so if you're under 18, turn back now, son. No NTR, and no full-on Yuri. There might be slight Yuri—like girls kissing and stuff during threesomes—but it's not that kind of Yuri where the girls fall in love with each other while in a relationship with the MC.---

In a morgue filled with the bodies of Uchiha clan members, he opened his eyes...A mysterious voice echoed in his ears...With a bewildered expression, he muttered, “Save the Shinobi world? What does that have to do with me, a mere Uchiha survivor?”