His Contractual Mistress - Chapter 519

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.

【Your descendants in the Immortal Cultivation World have offered a plate of snacks】【Incense Fire Value +10】【Would you like to reward your descendants?】Yang Genshuo was surprised to discover that offerings in the Immortal Cultivation Family game could actually appear in the modern world, and that modern items could also be bestowed upon descendants in the game.Years later, peculiar rumors about the Yang Family spread throughout the Immortal Cultivation World.“To break through from the Fetal Breathing Stage to the Qi Refinement Realm, one needs to refine a strand of heavenly and earth's spiritual energy. I've heard of Red Flame True Qi, Xuan Water True Qi, and Green Wood Spirit Energy, but Yang Dao-friend, this... Liquefied Natural Gas, what kind of spiritual energy is it? How is it condensed?”“I've heard that the Yang Family's Spiritual Plant Technique is incredibly sophisticated, with each mu of Spirit Rice yielding twice as much as top-tier Spirit Plant Families, all thanks to a strange secret technique the family disciples cultivate called 'hybridization'.”“The Yang Family’s art of elixirs is unrivaled in the world, with new elixirs constantly being created. It is rumored that a spirit of the elixir named 'Artificial Intelligence' tirelessly deduces elixir recipes day and night...”“Nowadays, the Thunder Cultivators of the Yang Family are exceptionally strong, all thanks to the Yang Family's effort in creating a top-tier Thunder Gathering Array. Thunder Cultivators who enter this array can increase their cultivation speed multiple times. It is said that the array eye is known as—the power station.“As the Yang Immortal Cultivation Family grew stronger, Yang Genshuo actually became the only Immortal in the modern world by consuming offerings!Years later, facing an endless stream of people ascending the mountain to seek the Dao, Yang Genshuo calmly said,”There are no immortals in this world; you must believe in science!“Then he soared away on his flying sword.

Three hundred years since the founding of the Great Jin Dynasty, the fortune of the country has been prosperous. In the imperial court, there are great Confucianists who make their promises.

Zuo Daoqi traveled to this world and became a little eunuch who was about to be thrown into the cold palace.

The court was treacherous, and the rivers and rivers were vicious. He just wanted to live on honestly.

But accidentally opened the script of life, can see through other people’s future scripts, and can get rewards after completing tasks.

The first thing that caught my eye was a little loli who was about to become an empress…

From then on, Zuo Daoqi planned to stay in the cold palace, study the game script well, and train the future empress by the way.

In my spare time, I’ll talk to the queen mother, imperial concubine, princess and so on.

His original purpose was to protect himself, so that he could leave the palace as soon as possible and become a rich man.

…

Until one day, a little eunuch came to Zuo Daoqi’s side,

“Nine thousand years old, the empress dowager said it’s time to serve her tonight.”

- Description from novelbuddy

[ Warning: Mature content (R-18)]In a world where the strong is king and weak don't have any right to even raise their heads.Eric, a boy of humble origin, was beaten to half-death state and thrown into the Demon abyss.Luckily, he survived and even got a life-changing opportunity in the form of [Godly Devil System]However...“What? I'm a half devil and the most suitable path for me is of a Dual Cultivator?!”Join Eric as he rises from the bottom, breaks the societal norms, and create a place himself for the world.