Ruinous Return - Chapter 27B2 –

Kurono Maou is a high school student who is sensitive of his sharp eyes and bad expression. No girlfriend but gifted with friends in his own way, he had been living a peaceful life.

He possessed the Xuan Gate Medical Arts and had fortuitously obtained a heaven-defying Spiritual Treasure!

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.

Death started her on the road of book transmigration. Transmigrating into different supporting females, snatching opportunities and men from the different worlds’ female leads’ hands. Hey, Female Lead, you can have the male lead, the supporting male is the one I want. Walking on this endless road, Xia Qiu did not expect that during these countless book transmigrations, the one she saved has always been the same person. He’s from outer space, trapped in the stream of time, with only a robot for company. Meeting her, falling for her…… However the sweetness isn’t easy. With a Boss as her man, Xia Qiu has a lot of worries. The Boss wants to bring me along as he destroys the earth, what should I do? #waiting online, quite urgent#

- Description from Novelupdates