The Duke's Son :Re - Chapter 257

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 a world where money and power trumps all, Ahn Soo Ho, A.K.A. Magician, uses his superhuman abilities and his knowledge of the intelligence world to climb to the very top of the totem pole.

“Stop crying. I’ll marry you. Calm down.”Cold. Emotionless.That is Duke Morvex, the monster duke whose half-blood lineage comes from the terrifying wolf demons.And I, Valerie Austin, wake up in the same bed as him, the ruthless duke who should never have touched me.But the biggest problem isn’t that forbidden night…It’s the truth everyone in the empire already knows:Duke Morvex is engaged and soon to be married.

After being killed, Xu Turan was given a system and got pulled into a certain thriller romance novel. There, she became the crucial female supporting role who seeks death. However, on the first day of transmigrating, her system was urgently recalled for repair as it was aging.

As their farewell was imminent, the system was worried about its new host so it repeatedly reminded Xu Turan: [Your role is to be a supporting character who is always seeking death. You do know what that means, right?]

Xu Turan recalled her rich experience of doing just that in her previous life and she replied affirmatively with absolute confidence.

So the system withdrew with its mind at ease.

After a few days, the system that had been away for repair finally returned. When it looked at the situation, it almost malfunctioned: [What are you doing?!!]

Xu Turan, who was busy arguing with the Evil God, answered without thinking, “I’m doing what you asked me to do – trying to find ways to die.]

System: […?!]

- Description from Novelupdates