The Monster Monarch System - Chapter 9: Monster Anomaly

Seol Woon-hwi, the Blood Heaven’s Righteous Blade, rose to power, becoming second to none under the heavens, reigning just beneath the sky itself.Yet, at the height of absolute power, he finds himself returned to his past—back to his days as the scorned illegitimate child of the Everlasting Snow Palace.

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.

Jun Xie was the number one assassin in modern earth. His skills and knowledge in the field of assassination were unparalleled, his accomplishments unprecedented, his reputation terrified the entire underworld. However, during a mission to retrieve a mystical treasure, a mishap occurred…

He is now Jun Moxie, a sixteen year old super level debauchee, sole heir to the declining Jun family. A family of valiant heroes, left with an old grandpa, a crippled uncle and a debauchee as the sole heir! Accepting the world’s criticism and cold stares with a smile, his new journey begins! His life will be carved by his own will! Rise to the top! Evil Monarch Jun Xie!

“This cup I toast to those I’ve killed in my past life. Forgive me, for there is no chance for you to have revenge. Gulp!

This cup I toast to those whose life I will take in my new life. Forgive me, for you are fated to die by my hands. Cheers!”

Alex Jin was just another overworked nobody until a truck crash sent him into the body of Valerian Nightshade—the cold-blooded villain from a popular fantasy novel. Destined to die early as the stepping stone for the “hero,” Valerian was powerful, rich, and feared… but ultimately doomed.That is, until the Villain Evolution System activated.Now, every villainous act rewards Alex with unimaginable power. Crush a rival? +100 Strength. Manipulate a noble house? Unlock a rare bloodline. Kiss the heroine meant for the hero? Well... let’s just say the rewards aren’t all measured in stats.To survive, Alex must outwit plot armor, bend fate, and ascend to the throne of power in a world that expects him to lose. But the deeper he goes, the more he realizes—being the villain might be the only way to save this twisted world.This time, the villain won’t die early. He’ll rewrite the story, one ruthless step at a time.