Mushoku Tensei (WN) - Volume 14

When the eldest prince Luo Fei reached 18 years old, the database automatically screened the genes of omegas across the entire empire for matching. The only son of a wealthy businessman, Mo Lin, had a gene match of more than 90% with the eldest prince. However, the moment he saw Mo Lin, Luo Fei learned that this omega is a sick child with paralyzed legs, hemiplegia, and severe mental illness???

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.

God gave me one more chance and finally came back after four hundred years.

As soon as I realized I returned, I decided that ‘no one should have pride.’

My goal was to destroy the country. So, I grew up with a genius prince who lived in hiding before returning.
He took up the empire for me and I left him for him to achieve his goal.

‘I came to pick you up Charlize Ronan.’ Dylan, who became a perfect tyrant after a few years, found me after searching all over the continent.

‘Why did you flee and run away?’

Bought it right away.