Reincarnated Swordmaster - Chapter 3

She was dressed in white, with a mysterious orchid imprint on her forehead, her skin like jade is always covered with a veil. Since childhood, she had left her parents due to her special status and lived her life with her master in the clouds. She was not yet ten when her medicinal skills were renowned in the world. In order to save the people, she descended the mountains, however, she encountered a storm on the way to the epidemic area. The man who saved her would tease her for enjoyment, little did they know…

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.

His name was 25. On Avalis, he was just one of many tasked with fulfilling missions for Earth’s people. This time, he was given a simple one—live as Zeno Han and have an ordinary life.Easy. Or so he thought.The moment he took over Zeno’s body, someone shoved a script into his hands. “You’ll be perfect for this role!” And just like that, he was on set.[Fame Meter: Unable to Measure. Off the charts.]Doctor? Check. Pilot? Check. Eunuch? …Regrettably, check. Every script forces him to relive past missions, and somehow, he’s nailing every performance. Now, the industry wants to make him a star, but can he still complete his mission? Or will fame—and the terrifying unknown of failure—be his final curtain call?

I have experienced all the eight sufferings of this world.

I do not ask for nirvana, but for you.

Wild and hard-to-tame demon (gong) x cold, ascetic and childish immortal (shou)

- Description from Novelupdates