Infinite Mana In The Oasis - Chapter 265 The Origin Of Hex Magic

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.

An editor at the prime of her life—and with maybe just a little too much free time—finds herself waking up in one of her favorite RPGs with no clue as to what's going on or how to get back home.This might be the part where others rejoice over getting whisked away to a world of wizards and magic, but she certainly doesn't think it's anything to celebrate about.After all, she woke up in the body of a small-time villain with some severe personality issues.

This is a time of great powers: The vast Persia, Sparta that was founded by force, Athens with its trade and business, Thebes the rising star, The ambitious Macedonia, The twin heroes of the Western Mediterranean, The rising Rome and so on.

This is an era of brilliant stars: Agesilaus II – the last king of Sparta, Epaminondas – the Rising General of Thebes, Philip II – the founder of Macedonian’s hegemon, Dionysius – the tyrant of Syracuse, Camillus – the Roman dictator and savior…

This is an era of contention among a hundred schools of thought: Plato – the great philosopher, Antisthenes – founder of cynicism, Pythagoras – school of number, Democritus – the encyclopedia scholar, Hippocrates – the father of western medicine, Aristophanes – the great dramatist…

What will the hero bring to the world when he comes to this age as a humble mercenary through rebirth?

After a night, surprisingly I acquired a husband!

Well, the fact is that after a one-night stand, I unwittingly signed a marriage agreement.

There isn’t a bad in-law relationship but instead a mother-in-law and daughter-in-law alliance.

The purpose of our alliance: Make my husband interested in women!

Frankly speaking, a man who isn’t interested in a woman … is he gay? Having a husband who is suspected to be a gay, I will fight for him and not let him go astray.

So I raise my eyebrows and with a wicked smile: My dear husband, wait and see how I am going to teach you to be a real man!

- Description from Novelupdates