The Scheming Billionaire's Heartfelt Devotion - Chapter 1 - 00: He Seems to Be on the Brink

Someone palmed out a blue dragon, which shocked the world. Someone smashes the green hill with a fist, and thousands of people admire it.

Some people live for thousands of years, just like gods. Some people are merciful and compassionate to the world.

In this world of panic, how can there be no place for me?

(The protagonist kills decisively. If you are not a virgin, kill if you have the strength, and if you don’t have the strength, you will die.)

- Description from novelbuddy

Chen Yan travels between worlds, ending up becoming an honorable prince in a medieval fantasy world. Yet this world was not quite as simple as he thought. Witches with magical powers abound, and fearsome wars between churches and kingdoms rage throughout the land.

Roland, a prince regarded as hopeless by his own father and assigned to the worst fief, spends his time developing a poor and backward town into a strong and modern city, while fighting against his siblings for the throne and absolute control over the kingdom. Join Roland as he befriends and allies with witches and, through fighting and even farming, pushes back invaders coming from the realm of evil.

- Description from Novelupdates

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.

Introduction: Su Muge, a God’s favored girl in the medical community, became an ugly girl due to time-space travel. Her father disliked her and her mother was too cowardly to protect her! Xia Houmo, a lonely wolf who was haughty and ever triumphant in battlefield, was asked by the emperor to marry a useless and ugly girl! On their wedding day, there was an assassin and he took her as a shield, as a result, she was wounded. Su Muge smiled slightly with crimson eyes, “Xia Houmo, I owed you, and I pay you now.” Seeing her red blood, his heart hurt… “Su Muge, you owed me too much and you must pay me birth after birth!” The heroine was not beautiful and not omnipotent, but she had golden light and magic hand.