Lord Of Doom!Reincarnated Into a Novel as the Strongest Side Character - Chapter 54: Heian-kyo City

When he arrived in this world, many familiar stories had yet to begin: Sleeping Beauty had not yet been born, the magic lamp lay buried at the bottom of a treasure vault, Snow White’s father had just remarried, and the Little Mermaid was still playing in the sea with her sisters. In the heart of the desert, the Land of Oz had not yet welcomed the girl named Dorothy.Then he came—the wizard of miracles and wishes.…Many years later, even illiterate children knew his legend: If you find yourself in the darkest abyss or hold the most fervent desire, you might encounter a handsome boy cloaked in robes in a distant forest or lonely mountains.He is the omnipotent wizard, the all-knowing prophet, the sage revered by kings, and the mentor of legendary heroes. He gave Pinocchio life, granted the Little Mermaid an immortal soul, and heard the pleas of both princesses and beggars.Now, it’s your turn.

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.

Under the vast immortal sky, the brilliance of an era is nothing but fireworks blooming at the fingertips.

Overlooking the earth, for thousands of years, life and death, where are they all? The Immortal Gate, the Dynasty, and the Supreme Holy Land are all just a handful of loess under the Immortal Vault.

A thousand years of splendor, and a smash into ashes.

Cinders sprout in the depths of the ruins, and you and I strive to be the trees that reach the sky.

What the hell is on the other side of the Immortal Firmament?

- Description from novelbuddy

After being reborn in a sci-fi ABO world, Xi Wei became the newly born son of the Imperial King. He thought, as the emperor’s son he could live a carefree and imposing life, but unexpectedly the First Prince is actually an omega? What the hell is an Omega?

There was an alpha who was born on the same day as the First Prince Xi Wei, the two children grew up together. When Xi Wei looked at the blonde child next door, he always felt that the boy was not pleasing to the eye, so as a child Xi Wei bullied him.

Until many years later …

Looking at the man standing in front of him who was one head taller than him, Xi Wei was dumbfounded.

–He tried to get out of the way, but eventually still fell into his childhood sweetheart’s clutches.

- Description from Novelupdates