Delve - Chapter 251: Homecoming

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 Academy City, magic and science coexist in an unwavering power struggle. Toma Kamijo, an academically-challenged student in Academy City, wields the power of the Imagine Breaker in his right hand, which allows him to completely negate all supernatural powers – as well as his own luck. When he happens upon a mysterious nun named Index, whose mind has been implanted with the Index Librorum Prohibitorum – 103,000 ancient texts banned by the Church – Toma’s luck is about to be pushed to its limits when he finds himself in the middle of a war he never expected!

“She had just traveled through time and now she’s doing a cesarean on her dead mother? And the children were still alive! Then, she had barely had the time to relish in her joy before the stupid villagers were going to burn her as a witch? Later, an emperor arrived on his horse and said, “Come with me.” The girl asked, “Why?” He answered, “Help my precious horse deliver her foal!”

Lin Fuyin had only thought of leading a quiet life with her two siblings after avenging her mother. She had never thought of being embroiled in the murder within the royal family as a village girl! Follow Fuyin through her tempestuous journey and as she stands at the top of the Wei Kingdom! The phoenix flaps its wings, about to soar…”

- Description from Novelupdates