Star Odyssey - Chapter 3500: Floral Transposition

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.

In the twenty-ninth year of the First Emperor, Bo Langsha was attacked.

When Ying Zheng merged the memories of the 21st century history doctor, looked at the mighty mountains and rivers in front of him, and said to himself, “In this life, my Daqin can’t die!”

- Description from novelbuddy

“An Ice Dragon with a legendary bloodline? Yeah… I tamed it.”Killed in an explosive lab accident, Liu Feng thought his story had ended. But fate had other plans. Reborn in a world where magic reigns and beasts dominate the wilds, science is no longer his weapon —magic is.[DING! You have been reincarnated!][DING! You have received a Talent!][Talent: Eye of the Beast King][Rank: SSS][Abilities: Speak to beasts. Control without bonds. See into their souls. Heal their wounds. Break their will]Gifted with one of the rarest talents in the realm, Liu Feng —now reborn as Aiden Aswald— seemed destined for greatness.But with power came a price: a cruel curse of immortality, one that chained him to an eternity of pain.At twelve, Aiden regained the memories of his past life —and with them, unlocked his beast-controlling powers.His first tamed creature? A terrifying Ice Dragon with a legendary bloodline, feared even among apex predators.Taming it should've been impossible. Surviving it? Even more so.But that was just the beginning.Now, Aiden walks a perilous path, forging bonds with magical beasts while uncovering the truth behind his curse. To break it, he must seek out the Essence of the Chronos Fire Dragon Beast.In a world where beasts rule, contracts are sacred, and survival is earned fang by fang... will Aiden rise as king —or fall as prey?

Originally born from a wealthy family, she ends up leading a vagrant life for fifteen years. However, when she is eventually found by her family, she falls into another devious plot and eventually dies tragically.

Fifteen years after her rebirth, ravenously raging for revenge, she tears down the hypocritical mask of the foster daughter who had taken her place, and reduces her greedy stepmother and stepsister back to their original sorry states.

To the jerk’s profession of his deep love for her, she only has one thing to say, “Get the hell out of my life. The love you speak of humiliates love!”

Regardless of the appearances of you monsters, I’ll take in it my stride with my capability, building a business dynasty of my own, sitting in the depths of my riches, bathing in the glistening limelight of the world.

A certain rich empire’s CEO: “Don’t mind me. I’m just leaving my mark here to declaring my possession rights; I’ll wait patiently for you to grow up!” The queen’s mighty return with commercial warfare fully within her grasp, she navigates the power struggles with skill and verve. When it comes to scheming conspiracies, all she has to say is, “Who are you again? Don’t even bother!”

- Description from Novelupdates