My SSS-Rank Class Is Blood Monarch! - Chapter 287 - - Back In The Tower (Part 11)

Jack Somnus was a mid-wealth professor of economics and a trading advisor for the powerful Johnson family. But after years of working for the Johnsons, he was abandoned without a word. He was laid off without as much as a severence package. Jack’s life got worse when he lost his wife. Depressed and alone, he got into an unfortunate accident. Instead of dying, he travels back in time to his teenage years. Now, Jack has a second chance to live the life he always wanted. He wants to be the one who controls, not the one being controlled. But his time travel hides a deeper secret, one that might throw him for a loop. [WARNING: CONTAINS EXPLICIT EROTIC SCENES]

Chi Zhao binds with the slag shou system, and if he succeeds in his missions, he will be rewarded.

But who said life is easy!

A rich old man who was slagged by him: “I know you love me. Your past pains, I’ve already investigated them.”

The star admiral who had been slagged by him: “Don’t be reluctant anymore! I’ve always known that you didn’t betray me.”

The entertainment mogul who was slagged by him: “Don’t make any noise. Honey, will you come home with me?”

The dark sentinel who was slagged by him: “Now, do you still want to say that it is not my child?”

The prince regent who was slagged by him said, “The mountains and rivers are yours, but you are mine.”

…

Chi Zhao burst into tears: “Boss, believe me just this once. Let me get the reward, okay?”

Thinking that the acting is very good, in fact, every day he’s spreading meng.

- Description from Novelupdates

The countries of Mephius and Garbera have been waging a war for ten years and are trying to put an end to this long fight through a political marriage between the two royal families. Orba, who was driven from his home because of the war and was forced to become a gladiator, looks exactly like the crown prince of Mephius, and it has been decided he will be substituting him during the wedding ceremony. On the other hand, Vileena, the princess of Garbera, has secretly decided to ensnare the crown prince for her own country’s interests.

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.