Number One Dungeon Supplier - Chapter 4: Grade 2 Meant Something

The messengers of destruction have once again been sent by their god, bearing the promise of apocalypse.Fire consumes everything, heralding the end of worlds— from Asgard to Atlantis, from heaven to hell. Once again, the fist of the god of destruction is poised to crush the very dimensions of existence, drawing ever closer to its goal. Amidst the chaos, a humble foot soldier—an insignificant speck on the grand stage—struggles to survive, fighting to climb towards the top.This is the combined story of Global Demon King: Starting as the Abyssal Dragon—Stronghold Legends and writer creativity

After a sudden and inexplicable transmigration, Maximus finds himself in a fantasy world where extraordinary power exists. But he is not without his advantages; he possesses a system that grants him the ability to become stronger as he takes on wives and birthed children.Determined to conquer this new world, Maximus uses his cheat to gather wives and birth children, building up his power and influence. As he gains more allies and resources, he sets his sights on the ultimate prize: ruling the world and surpassing even gods.However, the road to conquest is not an easy one. He must contend with powerful factions, rival conquerors, and unexpected challenges as he builds his ideal empire. But with his cunning mind, he is determined to succeed and become the greatest conqueror the world has ever seen.

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.