MTL - Hello, Mr. Major General - Chapter 41 Touch the inverse scale

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

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.

In the 41st Millennium, the planet I reside on, Cadia, was rated as the most habitable world for humanity. The birth rate once reached a staggering 35%. And I made an indelible contribution to this.Even the renowned expert in mass mobilization, Guilliman, once brought a team of specialists here to ask for my secrets.'Plants that have been extinct for ages, found only during the M2 era of Ancient Terra—how is this possible?' The entourage stared dumbfounded at the wilderness filled with carrots and potatoes.'By the Omnissiah! A lump of iron with no wires or power source can move freely and even possesses a Machine Spirit.' The Adeptus Mechanicus stood before the legion of Iron Golems, their hands trembling uncontrollably.'This thing is countless times more useful than an STC template.' The Tech-Priest stroked the Crafting Table, his bionic eyes fixed on the crafting recipe.'A device similar to the Webway?'...--This is translation but don't worry for I AM HERE, I will be the poison tester and remove all the poison I can to make the this Good story, Very Very Good.

2029 was supposed to be the year humanity moved forward.Instead, a failed military experiment tore open a gate to another dimension unleashing creatures that could shatter mountains with a single strike.From the wreckage, a new era began. Technology forged from energy crystals found beyond the gate and soldiers wielding beast infusions fuels humanity’s last defenses.Soldiers, mercenaries, and the desperate are sent to hunt the beasts... and one day, to face the terror that waits Beyond the Crimson Gate.But every step closer to the gate brings one truth into focus. What waits on the other side may not be killable.