Conquering OtherWorld Starts With a Game - Chapter 40.1: Brave Jean

Suzuki, an adult programmer, suddenly notices that he’s been thrown into a different world while wearing a casual clothes at level 1. He gained high levels and treasures after using the 3 times use-disposable-magic, Meteor Shower, once. After that he intends to do different world “sightseeing tours”? He meets 3 beast girls, beautiful purple and black haired sisters, and an eccentric blonde haired elf girl along with various people during his trip. Although there are occasional fighting with demons and demon lords, this is a heartwarming fantasy story at heart.

In the end-French era, after countless calamities, the era of cultivation is coming to an end. The last combination of air transportation and evolution has evolved into the treasure board, which was obtained by the last practitioner in the end-French era, which opened up a legend of wandering heavens.

- Description from Uukanshu

Divine techniques? Heaven’s gifts? Divine Weapon? Special Abilities? Unique Skills? Heavenly Talents?No, I don’t need them because I can create Heavenly Laws!In the boundless expanse of the starry seas, Lin Yuan wielded the extraordinary ‘Gate to the Myriad Realms’, he can transmigrate his consciousness in various world and comprehend any path!Embarking on countless odysseys, Lin Yuan’s relentless quest for strength knew no bounds. Through the cosmic tapestry of diverse worlds, he quietly forged his path, ascending from the depths of mediocrity to an unparalleled force.With each journey, he honed his skills until, at last, he stood as an invincible presence, dominating across all realms. The saga of Lin Yuan is a mesmerizing tale of cosmic ascent and relentless growth.

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.