The World's most Overpowered Side-Character - Chapter 5: The Contract.

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.

Lost in the vast expanse of space, trapped in the icy confines of a metal spacecraft, I was forced to face a horrifying truth.That I had transformed into a ruthless alien predator in a space survival game.

Ethan finds himself mysteriously transported to another world, where the strong reign and the weak perish.Welcomed by a kind farmer who decides to help him upon seeing his poor condition, Ethan begins to hope for a new life.However, his dream is shattered when an acquaintance deceives him, leading to his sale at the slave market. Desperate and confused, Ethan wonders what he has done to deserve all this.“Which deity have I offended to deserve all this?”Just when he thinks all is lost, fate has another surprise in store for him, once again changing the course of his destiny.

I drew a lottery at the Shopping District and won the privilege to go to another world. After drawing a lot of balls, unexpectedly I got a cheat-like skill. Silencing those who are noisy and getting hold of all the things that I want. I will satisfy all my desires.