Demon King of the Royal Class - Chapter 72

99 is one, and nine refinements are returned to Xian.

A young town boy, stepping on Xiuxian Road, is not a family, no gold fingers, with his own determination and wisdom, the nine major cultivation system, the nine realms step by step to the peak, and finally ninety-nine one, the achievement of true immortal.

- Description from Uukanshu translation

The world was destroyed, the apocalypse descended, a new era began, and the right to survive as a Lord was granted to every person.Domains, Heroes, Troops, Treasures, Resources—all of the countless servers constructed by the myriad continents were opened up.Qin Muye looked at his panel, which was akin to cannon fodder, and his domain with its damaged suffix, and felt a strong urge to cry but no tears would come.No divine talent, no hidden hints, no overpowered Profession.“If that's the case, then I'll just have to adapt and live in a different way.”

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.

Li Xiaoyu was reborn back to the difficult fifties.

Vows to save the relatives who died of starvation in the previous life.

In order to fill his stomach and prevent his family from starving, Li Xiaoyu took the space to work hard to farm pharmaceuticals.

Growing grains in space, ripening four times a year, and refining medicines in a medicine cauldron, the efficacy of medicines is increased tenfold.

Grain and supplies are as happy as a little hamster.

Helping relatives smoothly, the villagers survived the disaster year.

I even rescued a young man, and since then I have been missed by the big tail wolf…

- Description from novelbuddy