The Incubus System - Chapter 681: The Demon Hunter Chairwoman IV

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.

What if you could hack the strongest heroes and turn them into your devoted companions?Once feared as the Heavenly Demon, Zain stood above all—unstoppable, unrivaled, unchallenged.But his reign came to an end when so-called righteous cultivators banded together to eliminate him, believing they had purged the world of its greatest evil.Yet death was not the end.Reborn in a world dominated by heroes and champions of justice, Zain awakens a mysterious Hero Hack System—a power that doesn’t just defeat heroes but rewrites them.With a single command, he can shatter their convictions, twist their destinies, and rebuild them into something new.A ruthless warrior queen? Now a loyal blade at his side.An untouchable holy maiden? Now eager to obey.The strongest hero who once stood against him? Now kneeling before him, waiting for his command.With every hero he hacks, his harem of once-unshakable warriors grows. But as he reshapes this world to his will, one question remains—who gave him this system, and what price will he have to pay?They ended his reign once. This time, he’ll reign over them all.

Traveling to Los Angeles in the 1990s, Roland Allen, who had been beaten by society, thought that he would live an ordinary life in this life, but just when he was about to change careers, reincarnation began——

The number of roles is all determined by default, so they are all related households everywhere?

Sorry, as long as the hoe is swung well, there is no corner that cannot be dug.

- Description from novelbuddy

The leaves of the chess game beside Lanke, and there is no one playing chess among the old trees
Xing caused Tian Yuan’s first son, and then looked back at the vast mountains and seas
When he woke up, Ji Yuan became a half-blind beggar in a dilapidated mountain temple.
A real person has a sword and a magic stick has a mouth, which is the foundation for Ji Yuan to settle down in this terrifying world.

- Description from novelbuddy