Shocking the Nine Heavens With My Sword - Chapter 18 - : The Pursuit

Harry got a strange Life Achievement System which assigns missions that reward him for acting like a scumbag and earning Scum Points.Scum Points Could can be exchanged for powerful magical items, rare abilities, and tools that give Harry an edge in both life and business.At first, he resents it. Then he gets curious. And finally… he gets hooked.But being a scumbag is a high-risk profession. One wrong move, and he could lose everything, even his life. To survive this dangerous game, Harry must walk the line between manipulation and strategy, charm and ruthlessness.He’ll cheat, scheme, and hustle his way to the top.

Bathed in the love of her imperial family and her husband, Yun Shang was a spoiled princess and the envy of many at the Royal Court. Her life had been perfect right up till the moment when she realized that everything was just a sham, a ruse designed by the Empress to ruin Yun Shang. After enduring bitter treachery and being poisoned, Yun Shang died with a broken heart and an unfulfilled vow of vengeance. As if God was answering her final request, Yun Shang found herself reborn like an immortal phoenix. She was eight again, and all her memories from her previous life remained intact. The others, however, did not remember the events leading up to her death. Determined not to repeat her mistakes, Yun Shang planned to rain hellfire onto the treacherous, backstabbing villains for all the heart-wrenching pain they had once inflicted upon her. He was the handsome and smart prince of the Ning, who was revered as a battle-hardened general that knew no match in the world. He had thought he wouldn’t settle for anyone until she showed up. A seemingly innocent young princess and a gorgeous prince. Where would their relationship lead them?

- Description from Novelupdates

This is a cliché story about two young people saving the world.

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.