Ark (Published Novel) - Vol 17 Chapter 8

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.

Jiang Shang travels through the Zongman world, but the first world is Fuyuki City?

Joan of Arc, who was not supposed to be alive, came to her door and begged him to participate in the Holy Grail War?

I thought it was the beginning of hell.

At the critical moment, the system awakens!

Just make choices, or rewrite the plot, to get amazing rewards!

“Ally with Joan, get: Top Heroic Spirit Template!”

“Choose to save Matou Sakura, get: Imaginary Space!”

“Summon a mad-ranked servant, get: the holy gun of the end!”

The Holy Grail War begins!

Facing the arrogant King of Heroes, Jiang Shang showed his magic whip under the dull gaze of all the heroes!

“Arrogant tyrants should be beaten constantly.”

“I won’t stop until you admit your mistake.”

- Description from novelbuddy

Humanity was on the brink of destruction. Muyoung, an assassin from the Forest of Death, fell to his knees. There were corpses all around him. For years, he had worked for the Forest of Death and had finally been able to eradicate them. Now, he, himself, was about to die. He closed his eyes as he felt his heart stop beating.

Fang Shen’s eyes undergo perplexing changes after being hit by thunder. The change helps him acquire inscrutable and powerful life-death eyes which are able to launch many functions like clairvoyance. With the superb and magical eyes, he can dominate the world.

- Description from Novelupdates