In Different World with Naruto System (WN) - Chapter 223: Leave

Nagasawa crossed to Naruto Universe and was bound to Konohagakure.

If Konoha is severely damaged and destroyed, Nagasawa’s lifespan will be reduced.

He panicked at the thought of the upcoming Nine-Tailed Demon Fox’s attack , and the thought of Konoha getting destroyed left him in despair.

Fortunately, while bound to Konoha, he can obtain templates of powerful characters.

At the beginning, He got the Whitebeard template! Since it’s the Whitebeard from the Summit War of Marineford, he can use Tremor-Tremor Fruit’s ability and Haki.

Facing the Tailed Beast Ball, which terrorized Konoha Shinobi, Nagasawa leaped and shattered the Tailed Beast Ball with one punch!

- Description from Novelupdates

Deep Sea, the mental network connecting the Five Continents, is rapidly propelling human civilization forward, but no one knows that eternal night is coming. When the transcendence awakens, the grand buildings will collapse. When flesh and blood are bitter and weak, how can people ascend? The tale begins with an encounter and the receiving of a ruler carrying truth. Gu Shen, an ordinary young man, unveils a corner of the truth about this transcendental world and becomes the largest moth among thousands being drawn to a flame. When the bitter winter comes… I will ascend against the tide, overturn the thrones of kings, shatter the crowns of hypocrisy, and destroy the scepters of injustice. I will become humanity’s final Light Barrier.

I was a good looking prince when I was reborn, and because I could do indecent things as much as I like, I decided to make a harem while traveling with a beautiful female elf~

What happens when a scientist from a futuristic world reincarnates in a World of Magic and Knights? An awesome MC is what happens! A scientist’s goal is to explore the secrets of the universe, and this is exactly what Leylin sets out to do when he is reincarnated. Dark, cold and calculating, he makes use of all his resources as he sets off on his adventures to meet his goal. Face? Who needs that… Hmmm… that guy seems too powerful for me to take on now… I better keep a low profile for now. You want me to help you? Sure… but what benefit can I get out of it? Nothing? Bye. Hmmm… that guy looks like he might cause me problems in the future. Should I let him off for now and let him grow into someone that can threaten me….. Nahhh. *kill*-

Alternative: Leylin is transported from an advanced technological era into a medieval world— except there’s magic. Equipped with “only” his quick wits and an A.I. chip fused to his soul, he sets out to become the most powerful magus the world has ever known. In a land divided into the Light and Dark Magi, the weak can either be cattle or disposable slaves. Only the strong can determine their lives, and only they have the luxury for virtue. Yet strength is only a tool for Leylin, like any other. His goal, in the end, is his own.