I Became a 6★ Gacha Character - Chapter 482 - 60th Floor Battle Royale 2

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.

The prosperity of Piltover is on the surface, the barrenness of Zaun is miserable.

The able men of the Twin Cities, join Noxus, and I will lead you to the light!

– Ryan Meredith

The League of Legends fanfiction, starting with Zaun and Piltover, tells a story about the Empire.

Demacia to the west, Ionia to the east, Freljord to the north, Shurima to the south…

The empire has risen!

Also known as: “Heroes’ Testimony and Victory”, “The Noxian Way of the Far-God”, “The Four Souls of Chancellor Trifali”

- Description from novelbuddy

They love gold, and they love silver. Even more so, they love gems that dazzle, like stars across the skies.
Firearms, jewelleries, and precious metals; A collector’s world will not be complete without antiques.
Storage auctions, old goods trade, re-estate sales and gold-digging. But the truth is, if one wants to make money, then the supreme way is through searching for the legendary treasures.
Holding the fort, there’s an ocelot, a wolf, and an Andes condor. At the side, there’s a loyal hound, an irascible ape, and an African honey badger. Who said that you can only rely on humans when treasure hunting?!

- Description from Novelupdates

Here hundreds of countries compete for supremacy, here hundreds of schools of thought flourish, he brings the strongest family head system, establishes the most powerful family, and steps onto the highest stage step by step!