Dungeon Diver: Stealing A Monster's Power - Chapter 62

Luo Zheng is at the bottom of the Luo Clan hierarchy, despite his family being the founders of a power refining technique that could instantly defeat any opponent.

Yi Jiamu was a patient with the ‘Ability Deficiency Disorder’ and he inadvertently attracted Gu Yesheng’s attention.

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.

Qin Lin was electrocuted by playing a nostalgic “Ranch Story” game, and suddenly gained the ability to enter the game. He also found that he could bring the watermelons grown in the game out of reality.

At first, he calculated that a pound of watermelon would sell for 2 yuan. As long as he sells 10,000 catties of watermelon seeds in the game, he can earn 20,000 yuan a day.

Later, he discovered that by upgrading pastures, he could obtain advanced crops beyond the world, raising livestock to obtain advanced livestock breeds that were far beyond the world, and building factories to obtain various formulas that were far beyond the world, and everything was different.

- Description from novelbuddy