Star Odyssey - Chapter 3578: Lu Yin And Jiu Xian

Attribute Classification: Overhead/Western Magic/Strong Attack/Sweet

- Description from novelbuddy

After getting forcefully reincarnated into a world of an otome game he has no clue about, the protagonist is then killed and brought back to life by the prideful villainess with one desire.

To rule the world.

As the ruthless girl’s Eternal Servant, how will he dodge the fate that the game system has in store for him?

Due to his own carelessness, Duanmu Huai finds himself transported into the world of the game “Star Ocean Online.” Starting from a humble core capsule, Duanmu Huai ventures across the starry sea to countless worlds. He awakens powers that have long been dormant, confronts threats lurking in the depths of the universe, and sets his sights on dominating the galaxy!

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.