Start by Spending One Billion [Entertainment Industry] - Chapter 120

A simple childhood love story.

The female lead’s name is Xiao Tu (Bunny) and the male lead’s name is Ling Chao (Super). As neighbors who were born a month apart, they grew up, went to school, and graduated together.

Tu Tu is a cute and good girl. Even though she’s not really smart, she’s not stupid. Since she is skilled in martial arts, the guys are scared of her.

Ling Chao is smart and cool, but also stuffy and quiet. He is the brainy type who excels in studies.

Tu Tu’s mother wishes her daughter would grow up and marry Ling Chao, but her father disagrees and wants Tu Tu to get to know other boys.

- Description from Novelupdates

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.

Young Lin Yi, betrayed by his beloved, had his core taken away and became a pariah despised by all.At a fortuitous moment, Lin Yi acquired the ancient legacy 'Chaos Sword Body Technique', rising against the odds to embark on a path of revenge!“Those who have wronged me, Lin Yi, shall be repaid a hundredfold!”

I became a scientist for an evil organization.…But I’m too competent.