Mesmerizing Ghost Doctor - Chapter 2570 - Ling Tianyu

Three years ago, Yun Qing Yan fell into the Immortal Realm from the mortal realm. Three thousand years later, he became Divine Emperor Yun who shook the entire Immoral Realm. Breaking through the void and returning back to the mortal realm, Yun Qing Yan discovered that only three years’ time had passed here. “In the past, I did not possess the power to protect the people I hold dear. Now, I want the entire world to grovel at my feet.”

- Description from Novelupdates

Rex was an ordinary salaryman, resigned to a dull life of monotony in a towering megacity. But his world shatters when he’s conscripted by Nexum Dynamics, a ruthless megacorporation, and thrust into a brutal war for a barren, alien world. The planet holds unimaginable riches, but it’s also swarming with the Krhyssari, an insectoid race that dominates the surface with their hive-mind precision and relentless aggression. Amid the carnage, Rex had an extraordinary encounter with Cleo, an ancient AI, a survivor of a long-extinct civilization. Cleo isn’t just an artificial intelligence; she’s a consciousness imbued with memories of her people’s interstellar empire and equipped with advanced bio-nanotechnology. Offering Rex a new purpose and unmatched power, she transforms his fragile human body into a hybrid of living metal and flesh, making him the ultimate weapon. But Cleo is more than a tool of war. As she journeys alongside Rex, her cold, logical algorithms evolve, shaped by his humanity. Together, they form a bond that transcends the boundaries of man and machine, discovering love in the midst of chaos. As Rex and Cleo fight for survival, they uncover a shared ambition, to rise as intergalactic overlords, uniting or conquering the galaxy.

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.

No sign in, no punch card.

Do not rely on breathing, do not rely on walking, do not rely on heartbeat.

The system is produced in one step

- Description from novelbuddy