Rest in a Demon's Embrace - Chapter 195 - “Heartless Young Man”

Liam Sera Banfield is a reincarnator.

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.

“Your Majesty, someone cursed the Imperial Concubine to be a demon star.”

“Cut his tongue and feed it to dogs.” A certain King said in a light and gentle manner.

“Your Majesty, someone’s hand accidentally bumped into the Imperial Concubine.”

“Chop his hand and feed it to wolves.” In an indifferent manner, a certain King said possessively.

“Your Majesty, someone said that the Imperial Concubine ran away.”

“Ran away?” A certain King’s sharp eyes narrowed, then said with a sneer: “It’s best if she doesn’t get caught by this King, otherwise this King will let her become aware of what ‘wanting to stop but can’t’ means**.

A modern era crossed over to become a wolf-girl. She originally believed that she could dance around with wolves, and in the end she truly did, but this ‘wolf’ was one of those wolves. He was a perverted wolf!!

- Description from Novelupdates

Liang Muqiu seriously doubted if he had read the astrology forecast when he went out today.

He borrowed a fire in the bar, but borrowed it from his ex-boyfriend.

It is said that old partners would never contact each other. However, they hadn’t seen each other for seven years, yet this bastard was not only not old, but also more handsome than before.

Especially when Cen Nan lit a cigarette for him in the dim light, his eyelashes drooped slightly, like when he kissed him under the blossoming tree seven years ago.

Liang Muqiu: Damn it, why was he still a little excited?

It took a long time for Liang Muqiu to wake up.

From the moment he saw Cen Nan, what he wanted to borrow was not fire, but a kiss of reunion after a long separation.

After seven years of separation, he still loved the same person.

Coincidentally, so did Cen Nan.

- Description from Novelupdates