Hate Me, Witch! - Chapter 38: Art Is… Patrick Star!

The daughter of a duke, the stuttering Maximilian, married a knight of lowly status at her father’s coercion.

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.

[Warning: Mature Content and a ruthless, villainous, badass mc!]Kael Draven was once the feared leader of an underground mafia empire. A shadow ruler who pulled the strings behind the scenes.But power comes at a price. Kael learned that the hard way when a bullet pierced his ear, and his trusted ally betrayed him, bringing his life to an end.Bang!As his empire crumbled and his body hit the cold floor, all he could think was, ‘What a pathetic way to go.’Instead of hell, Kael woke up in a far more dangerous world, with a body stronger than ever—youthful, shredded, with muscles for days and an ego that could crush mountains.His title? Master of the Crimson Maw.He now led a bandit group that had angered a mysterious force and been wiped out—except for one survivor: a strong, silent gladiatrix who wanted nothing to do with him.To make things even more interesting, his body bore a glowing tattoo that whispered in his mind: “Bond. Through body. Through soul.”But Kael wasn’t one to back down. He didn’t like losing.So what if his base was a dilapidated shack? So what if his army was just one extremely voluptuous warrior?Kael wasn’t here to play small. He was going to turn this ragtag bandit group into a force feared by all, with a harem of deadly beauties who would bow to no one but him!Welcome to the Crimson Maw. Where the training is brutal, the beauties are overpowered, and the only thing more dangerous than an enemy is the bandit king himself.Let the grind begin!

Starting over once more, he has entered this “living game” again in order to control his own fate.

This time, he will not be controlled by others.

Previously the Level 200 Sword King, he will rise to a higher peak in this life.

Methods to earn money! Dungeon conquering strategies! Legendary Quests! Equipment drop locations! Undiscovered battle techniques!

Even the secrets Beta Testers were unknowledgeable of, he knows of them all.

Massive wars, life advancement, entering Godhood, sword reaching to the peak; a legend of a man becoming a Sword God has begun.

- Description from Novelupdates