MTL - Remarry, No Way! - Chapter 571 I hope that I can’t come back.

She, a 21st century mercenary queen, had crossed over into a tragically betrayed body of a waste. Waste? She will show them what it means to be a waste! Betrayed? With the Ancient Manual in her hands, she will astonish all the despicable men and cheap women!

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.

Lin En transmigrated into a magical world that resembled medieval Europe but had the power of magic.Here, magic could affect and control basic particles, which was based on scientific theories that served as magic formulas!The wizards, who were actually scientists, were struggling to explore the truth of the world under the chase and blockade of the church. Lin En’s arrival sparked a renaissance of the alternate world…The white phosphorus fire, known as the Flame of Hell, the liquid nitrogen field of extreme cold, and the resonance frequency that kills without a trace… A few years later, the Holy See gathered all countries to the city, known as the legendary wizard, the pioneer of magic Lynn under the gaze of a group of wizards, wrote down the mass energy equation known as the ladder of God by later generations! Lynn looked around the crowd and said nonchalantly. “Mass and energy are interchangeable, and based on this theory, I have developed a powerful forbidden curse… It’s called — “The Big Nuke!”We will re-examine the world from the perspective of magic, where science is magic, and magic is science!

“I’m a warrior from the alternate universe.”“The Goddess summoned me to this world to defeat the Devil that has imperiled the world and to restore peace to the world.”“I understand that it’s my cardinal duty. Since I’ve been summoned to become a Warrior, I’ll do my best to beat my opponent even if he’s the almighty Devil.”“Don’t ask me why. That’s what the book says.”“But… isn’t this development straying from the plot?!”This is the beginning of a scam in an alternate universe. It is also the story of a warrior with a mission to defeat the Devil. At the end, he realized that he had been duped instead.