MTL - The Empress’s Gigolo - Chapter 1183 Dark God Reappears

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.

Luo Ling, an expert in the art of disguise, was bound to a System and was eager to begin his task.

As a result, before even successfully completing a mission, he got married!

At a 36 degree angle, Luo Ling sorrowfully looked up into space: “Tong’er, tell me, do I still have a chance to free myself?”

System: “… Your man is behind you.”

Luo Ling: “!!!”

The person who arrived, gathered Luo Ling in his arms, hugging him from behind as he said in a bewitchingly dangerous tone: “Based on your thoughts, it seems that I have not given you enough love. So let’s proceed in exploring ways to continue a new life.”

- Description from Novelupdates

Is he a genius in the spotlight, or is he a madman behind the scenes of the Second Avenue?—-After getting the final relief from his past sufferings, Chu Jiashu was given a second chance when he found himself in the body of an infant from an aristocratic family of Hall. Now, nothing is going to stop him from achieving his long-cherished dream of acting. Enter Renly Hall, a Hollywood miracle of 21st century.

Fang Ze traveled to the world of psychic forensics and activated the detection system.

Since then, the world has gained a crime-solving wizard. In just one year, Fang Ze became the captain of the police force.

Suspicious disappearance cases, corpse dismemberment cases without clues, heinous vampire cases…

With his keen judgment, Fang Ze relied on the assistance of the system to grow all the way.

With the passage of time, Fang Ze suddenly discovered that this world seems to be more than just a psychic forensic doctor…

- Description from novelbuddy