Hikari: Rise Of The Weapons Master - Chapter 211 Bringing Him To Their Side

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.

Reincarnating into the world of Jujutsu Kaisen, he became Gojo Satoshi, the twin brother of the strongest sorcerer, Gojo Satoru. That should mean he’s destined to be the most powerful Jujutsu sorcerer, right?Unfortunately, fate had other plans. Nearly killed by Satoru in the womb, his cursed energy was devoured before he was even born. But at that moment, he awakened the [Shinigami Fusion System].Since he couldn’t become a Jujutsu sorcerer, he would forge a new path, a Shinigami with Heavenly Restriction!Thus, Gojo Satoshi, born without cursed energy yet possessing the legendary Six Eyes, became the true nemesis of Jujutsu sorcerers.

The beautiful neighbor he had known for about half a year suddenly asked him if he wanted to be together.Liu Xin'an considered for a brief few seconds before nodding with a smile.But a few days later, she disappeared without a trace.Late, she reappeared on television.Liu Xin'an: So the girlfriend I liked turned out to be a big-time celebrity?

A teenager who unexpectedly gets transported to the modern world from ‘the world of the immortals’ . He finds himself in the body of an ordinary guy. He wants to go back to his world and for that, he will have to practice to get stronger and investigate the reason why and how he crossed through to this world.