The world has turned into Hell's Game, why should I stay human?! - Chapter 13 Convergence

I was reborn as the villainous daughter, Yumiela Dolknes, in the world of an otome RPG game. Yumiela only had a small role in the original story, but after defeating the Demon King, she will appear as the Hidden Boss with a bonus specs to solo fight the Hero party.

Having a gamer-spirit, I’ve been raising my level since I was a child. By the time I enter the academy where the game stage is, I was level 99.

I wanted the heroine and the capture targets to defeat the Demon King, but they just flirted around and didn’t raise their level. Moreover, they treat me as if I’m the Demon King just because I have dark hair and use dark magic.

It’s a story where I aim for peaceful days.

Dual Cultivation is an art. The more you focus on doing the art, the worse it becomes. Only when doing it becomes part of the art itself, does one truly experience it to its fullest.

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.

She had a lifetime of fake virtue without receiving a virtuous ending. In the next lifetime, she controls fates with the flip of her hand. To the jerk who wasn’t faithful, she’ll draw a premature death talisman for him. For the poisonous step mother, she’ll send a death flower. For the step sister who is two faced, she’ll personally rip off that fake pretty face!

But when she personally offered up her body to her nemesis because of a child who she had no fate with, something unexpected happened. The night of the big wedding, the groom changed and a cold and luxurious man pushed her down. “You can marry whoever you like, but you can only give birth to my children!”

- Description from Novelupdates