My Identities Were All Exposed After I Was Pampered by Everyone at My Grandfather's House! - Chapter 293 - Second Brother Is Here

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.

They say the greatest blessing is marrying the idol you always dreamed of.

A man dies and for some mysterious reason is given three wishes.The man, a pervert and even degenerate (just a little), asked to be sent to a world full of sex and lust, just for pure fun, unfortunately he was not very specific and ended up going to a world much bigger than he could imagine.His other wish was the System he read in one of the many stories he read, the System of [The Gamer], which due to various reasons, perhaps due to laziness of the person who created it, the System is not 100% identical.But this didn't affect our protagonist much, who had the opportunity to create his own appearance and decided for nothing less than a hot Futanari with a big dick!

A girl who calls herself a demon appeared before a timid student named Fumio Kijima. The girl claims to be a campaign girl from the demon world and she gives him the ability to “summon a room” from nothing but thin air.

At first he doesn’t abuse his power and uses it as a convenient ability in his every day life. But one day he is bullied by his classmates under a false pretext and is made to suffer. In the past he would have wallowed in misery and cried himself to sleep, but now he had a power to call upon.

“I will make them regret it!”

Using his powers to summon his “room”, he begins his era of confinement and brainwashing to achieve his goals.