Rise Online: Return of the Legendary Player - Chapter 889: Sixth Circle, Heresy (Final Part)

When Roland crossed Middle-earth with the Lord of the Rings system, Gandalf was organizing an expedition, the king under the mountain still did not return to his throne, the Hobbit’s adventure had not yet begun, and the world was still shrouded in shadows…

- Description from novelbuddy

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.

After the divorce, the ex-wife disappeared for four years and unexpectedly gave birth to a pair of twins! Upon reuniting, Third Young Master Shen continuously pressured her into marriage, but the ex-wife's heart was tightly shut. The soft and adorable daughter was worried, saying: “Uncle Shen, why don't you kidnap me and threaten my mom to marry you?” Clearly, she is his biological daughter. The arrogant son, on the other hand, specializes in ruining plans, revealing someone’s embarrassing photos: “If you keep pestering my mom, I’ll send this to the parent group!” He's clearly out to get his dad!

The Red Dragon came from the vast wild wastes, coveting all the strength in the world. It once had countless titles: Mountain's Wrathful Flame, Infernal Calamity, Crimson Emperor, Ashen Dragon......The world trembled under the shadow of the giant dragons. He stirred up the craze of the magic industrial revolution; in the empire he established, Wyverns roared, artillery fired in unison, and steel beasts appeared in the sky and on the land, while disasters from another world rampaged everywhere.“Submit, or die.”Cassius spread his wings, blotting out the sun, and gazed down at the trembling humans, elves, and dwarves below, saying thus.......It is a story about a Red Dragon with a player template conquering, ruling, and transforming an alternate world.(Pseudo of DnD, The Fourth Calamity, Red Dragon)