The Main Characters That Only I Know - Chapter 56:

A professional gamer dies unexpectedly during an E-Sports tournament and is sent to Valhalla, a heaven reserved for only the greatest of warriors.

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.

The day a mysterious darkness enshrouded the world. It was theorized that the earth’s magnetic field had been changed, the data that corresponded to it also changed. The previous academic knowledge had been overturned, and numerous things had to be re-explored.

The science that humanity was familiar with had been disrupted, including the genes of human beings. One of the largest disasters brought by the change was that 80% of humanity transformed into zombies. After years of struggling, a few lucky survivors would evolve and awaken a power inside themselves. Chu Han was never that lucky.

While holding on against the first wave, humans weren’t the only ones getting stronger. Soon, stage 1 zombies evolved into stage 2 then 3 and so on. 10 years after the mysterious meltdown, the world of man belonged to the zombies. Humanity was nearing the of the end of the eschatology.

One day, Chu Han consciousness came back ten years before the end of the world came. He was awakened by a loud noise in a dormitory in Minqiu University. With only 1 day to prepare before the meltdown begins, he slowly begins to realised that he had undergone a rebirth. A power was awaking inside of him now despite never appearing in the hellish future. It calls itself the meltdown system.

Despite losing the monstrous strength gained through years of harsh training, this system claims to trade kills for talents. This is a story of a collapsing world, a meltdown system, and Chu Han being on stage as he travels to save those he could not save before.

- Description from Novelupdates

Finding an ancient treasure was not as fortunate as one might expect. As soon as Bai Rouyun had left the grave, countless sects and hidden families set out to kill her for the sake of obtaining her treasure for themselves.