Reborn at Boot Camp: General, Don’t Mess Around! - Chapter 4703: Beaten

Pinnacle of martial, mountain shifting and sea filling, catching stars and seizing the moon, reverse the flow of time!

Extremity of the sword, one sword to form the dao, one sword to reach the immortals, one sword to break the laws!

The young Li Fuchen, chanced upon the Golden Talisman which allowed his spirit soul to constantly evolve. In this world where prodigies and experts were everywhere, he used the sword in his hand to ascend to the absolute pinnacle.

The world will decay one day, but my reverence shall be eternal.

- 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.

Yeon-woo had a twin brother who disappeared five years ago. One day, a pocket watch left by his brother returned to his possession. Inside, he found a hidden diary in which was recorded “By the time you hear this, I guess I will be already dead….”

A magical ring and a mighty spirit inside the ring, coupled with a genius who lost his cultivation and got named worthless trash. That’s Xiao Yan, the poor genius. You think Xiao Yan got it bad? Well, you clearly have not met Jing Yan.

Jing Yan was once the shining star of the whole East City. However, his cultivation dropped because of the Universal Ring that was left to him by his dead grandfather. Without anything but the Universal Ring, he will once more rise towards the top and beyond!

He is Jing Yan, The Universal Sword God.

- Description from Novelupdates