I Became the Male Lead's Stepmother After Transmigrating - Chapter 5

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.

This is the story of how I became the greatest genius in the history of humanity, destined to go down in the annals of history for all eternity!This is the story of how I made humanity what it is today.It all began on a fateful night in New York. With a certain peculiar dream.The Universe is grand and mysterious. What's important remains hidden...

Upon awakening, Su Changkong found himself transmigrated to a world thrown into chaos by war and rampaged by demon monsters, where his martial arts talent was mediocre. However, Su Changkong discovered that as long as his own “life span” increased, his talents and potential could also be “limitlessly” enhanced!Cultivating the Health-preserving Fist technique and practicing the qi of longevity! The path to immortality is littered with corpses, and Su Changkong embarked on a Martial Arts path where he would not perish, even if heaven and earth were to be annihilated!

Side story of Kyoukai Senjou no Horizon bundled with the first press release of the 1st, 3rd, 5th and 7th Blu-ray volumes of both seasons of anime.

This side story follows Asama, Kimi and Mitotsudaira aboard Musashi one year before the beginning of the main story, as Asama is considering to create a music band together with her two friends for the next festival in Aki, a territory under the governance of K.P.A. Italia.