One Piece: My Crew is from Other World - Chapter 573: The Origin of God Confirmed!

An ordinary student accidentally traveled into an other universe and became the king of a small kingdom. He had gotten a “Cheating Code” of life and was able to complete something extraordinary. This is the story about a king that was able to conquer continents and leave behind him an ultimate legend that will be recited between every generation to come.

- Description from novelupdates

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

In the 5th year of Konoha’s founding.The battle between Hashirama Senju and Madara Uchiha at the Valley of the End had come to a close.In order to treat his elder brother’s injuries, Tobirama Senju resurrected a medical ninja from ancient times, hoping that this individual could prevent the injuries from shortening his brother’s lifespan.This medical ninja’s name was Emiya Shigen.

John Mirage was a young hacker, waiting for his court trial, when he was presented with a choice. Joining a secret ‘fake’ government program, he ended up playing right in a totally unexpected foul play from the future!He found himself travelling into the future, inside a VR game called “Athanasia”, where he gained a Hacker System, lots of abilities, and was facing a grand scheme that ran deeper than anyone thought!The fight between humans and machines in the future wasn’t just brutal and cunning; it also spanned to include the VR game, the real world, and even a totally alien world, with different powers in play, even alien races! And John was standing right in the heart of all this, as the variable and anomaly no one expected!Armed with his system, John will struggle to complete quests, learn new abilities, hack everything, increase his system synchronisation level and upgrade his system to become a powerhouse and an unexpected variable in that war!John will fight on different fronts, against overwhelming odds, and find a way to hack his success through all adversaries!