Tensei Shitara Slime Datta Ken (WN) - Chapter 387

I am the sword.

Killing a man amidst a thousand miles, no one dares take ten steps.
Killing a man amidst a thousand miles, no one can take ten steps.
Killing a man amidst a thousand miles, ten steps? Not possible!

I am the sword, the sword is me,
On the path towards heaven, each shall wield their own.

- Description from Novelupdates

Chu Nan was just an ordinary student, but because of an accident, he obtained the data collection, analysis and processing ability equivalent to the most advanced optical brain.

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.

A youth crept on the ground in a snowy night. Hours ago, his tendons were cut because the girl he liked plotted against him. A mysterious middle-aged man saved him, and a pair of gigantic purple pupils appeared in the sky. Under the thunders and lights, the rare Demon Pupils and Sacred Body were awakened. That was what he should have been.

However, in this world, strength was the only way to support a man to live. His adoptive father died for covering him. His true love fell into the abyss for saving him. He wanted to rise up, to take revenge, and to protect the ones he cared about.

Occasionally did a strange figure confuse him. Behind the huge demon pupils, he often saw a thirty thousand feet tall black figure. What was it? Who was that?

It was said that the ultimate bloodline of the universe was the Primal Chaos Divine Body. It was a divine existence which could break the heavens and annihilate the world in a second. However, this sort of divine body had been extinct ten thousand years ago.

Could it be that apart from the Sacred Body, there was another body in him?

- Description from Novelupdates