MTL - Raised By the Whole Earth As a Paper Man [Interstellar] - Chapter 90 .90·

Zhong Li, an orphan in the 21st century, was wondering how to collect the fees for his college study on the street, when he was suddenly hit by a car, which threw him into a river. An orphan’s disappearance would not bring too much attention to the world, but this accident gave Zhong Li another chance of living a glorious life in an immortal world. When he woke up, he found himself lying in a magnificent yet strange palace built of all gold, but had no door. An immortal claimed to be his savior and wanted to train Zhong Li with all of his cultivation methods, only because he was too lonely and wanted a disciple to keep him company. When Zhong Li finished his study, the master would tell him how to go out of the palace. Zhong Li never thought that the path to immortality would bring him to the fate of becoming a dragon.

- Description from Novelupdates

An accident gave Ye Han a magical ability to see through. Since then, his life has become rich and colorful. He has developed the strongest business empire, dominated the gambling world, and rejuvenated his medical skills. He has become a master of medicine and Taoism. The goddesses rushed towards him one after another. As a man, and a limited edition man, Ye Han was under a lot of pressure and had to go on an exploration with a few tomb robbers. However, a shocking secret from ancient times to the present gradually emerged. in front of him!

- Description from novelbuddy

Mysterious gates appeared all around the world a few decades ago. Beings emerged from the gates and brought disaster upon humanity. Humanity called them Demon Spirits. It wasn’t until the advent of Demon Suits and Demon Suiters that humans stood a fighting chance.For some perplexing reason, the world’s number one Demon Suiter, Li “God” Xiu abandons his identity to start over again as a newbie trial-taker. He enters the gates to participate in all sorts of trials, in a bid to seek out the reason that enticed his best friend into becoming a trial-taker.These trials weren't the run-of-the-mill dungeons, ranging from game sports (soccer, basketball, baseball, etc) to athletics. Just as fortune favors the brave, what would Li Xiu obtain on his quest?“Are you telling me he’s a greenhorn?” the other trial-takers frustratingly ask while watching Li Xiu's feats that prove why he's the number one Demon Suiter.

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.