MTL - Bestial Blade - Chapter 72 So fast knife, so much energy

The protagonist, Winnie (文尼), confesses his love to his childhood friend—the princess he’s been secretly in love with for years—but is brutally rejected in public. His heart shatters, he’s humiliated and ridiculed, and he collapses unconscious. When he wakes up, he vaguely remembers his past life’s memories and realizes he has transmigrated into the world of an otome game he played before. At first, he’s thrilled, thinking, “Nice! I must have been reincarnated as a villainous side character who disrupts the protagonist’s romance, right?” But then… surprise! He’s not just the villain—he’s the “Saintess”!

I was reincarnated into the world of Academy City.Since things turned out this way, I decided to aim for a decent job and live a happy life.As long as I catch the villains who will become the Great Villain, there shouldn’t be any problems.“Greetings. I am Ahn Woo-jin, a second-year student and the 45th Disciplinary Committee Leader this year.”And so, I became the Disciplinary Committee Leader, leading the top-ranked enforcement squad.

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.

The Capital’s girls look on with hatred, “ You’re just a country girl without any knowledge. Do you have Cloud Shop’s clothes? Do you have Brilliant Treasure Pavillion’s jewellery? Do you even know how eminent and domineering the famous Yue Wang is?