How To Be A Demon lord: The Former Hero's Journey As A Demon Lord! - Chapter 18 It Was A Matter Of Dishonor

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.

After traveling for three years, Lin Yu was drawn into a horror game unexpectedly.

However, he discovered one thing.

The dungeon boss feared by countless players turned out to be the little loli who called her big brother next door.

then.

In the horror hospital, the director of the hospital turned out to be the uncle downstairs who made him and his granddaughter fall in love.

In the bloody slaughterhouse, the existence known as the bloody butcher turned out to be the uncle upstairs who wanted him to be his brother-in-law.

In Changteng Ghost School, the woman who frightens countless students is actually the long-legged sister Yu who invites her to her house for dinner whenever she has nothing to do.

…

Traveling through three years, you told me that this place is actually a horror game world?

(Introduction is weak, please read the text)

- Description from novelbuddy

Zong Shou is a player of the historical VRMMORPG “God Emperor,” and him being one of the “Seven Emperors” within the game.

For unknown reasons, Zong Shou finds himself transmigrated into the past, a period just before the “God Emperor” game history started! Possessing the weak body of a monster princeling in the process.

Zong Shou adventure describes his struggles to stay afloat in a merciless environment, and rising up despite all adversities, of course, surrounded by beauties along the way.

- Description from Novelupdates

To pick is to choose. This is a story about choices. Three thousand worlds full of gods and demons, with a daoist scroll in your hand, you are able to control the entire universe…