MTL - True and False Daughters Joined Forces [Metaphysics] - Chapter 207 Miasma

A young man with no spiritual roots. A person who is thought of as trash by others. He constantly acquires various items thought of as waste by the cultivation world. No matter if it is garbage pills or useless materials, he will take them all!

- Description from Novelupdates

After being defeated and captured, the dragon-slaying hero Leon became a captive of the Silver Dragon Empress.With a resolve for certain death, Leon unexpectedly turned the tables and successfully imp**gnated the empress on his verge of dying.He thought that this would be enough to let the empress live with shame for the rest of her life and he also fulfilled his duty as a dragon slayer.However, two years later, when Leon opened his eyes, he found a little dragon girl with a tail lying beside him……

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.

Entering the mortal world for a hundred generations, do not compete for the youth of one life, but only for the day and night of a hundred generations.

Seeking immortals in the world of mortals.

My name is Li Qing. I have escaped from the mortal world in the third life, entered the Tao in the ninth life, and become immortal in the hundredth life.

(longevity stream, non-simulator, non-reincarnation rebirth)

(Bai Shi Shou Yuan, One Life Life)

- Description from novelbuddy