Tokyo: Rabbit Officer and Her Evil Partner - Chapter 50: The Wise and Reliable Senior Watanabe Shun

In the myriad realms, legends rise and fall in the countless eras.

“I’m sure we’ve all had that weird kid in our class.”“You know, the one everyone avoids like the plague.”“The moron who always comes to school with messy black hair, torn-up clothes, and so many bruises on their body it looks like they were mauled by a bear.”“I know that kid well—”“Because I’m him.”[DING!][YOU HAVE AWAKENED YOUR BLACKSMITH SYSTEM]“Blacksmith system? What the fuck is that?”It’s the power to forge.The power to create weapons that can split the heavens themselves.Weapons that can challenge gods, rewrite fate, and reduce galaxies to dust.Weapons that can cut through time and space.With the Blacksmith System… you have the power of creation.Do you accept?[Y/N]

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 a modern world, a professional assassin was murdered by her beloved and found herself revived in an ancient world as a general’s daughter with a weak physique. She was engaged to a prince, but because she did not have a nice appearance, her fiancé and sister attempted to kill her. Although she had to struggle to survive, there were also those who unconditionally loves her that supported her in her time of need.