The Principle of a Philosopher by Eternal Fool 'Asley' - Chapter 14.4, Everyone’s After Stories, And A Few Words From The Grand Philosopher Part 3/4

A master assassin transmigrates into an interstellar era.

Other players were responsible for competing in the e-sports arena, while he was responsible for stringing up and beating up the other players.

His sword was hidden during the peak of day, and he was a gentleman who arrived in a flash of light;
As a vanguard of the eternal night, he was the variable between life and death in the world.

“As you know, the Star League’s difficulty levels are arranged in this way:
Paradise < Simple < Normal < Difficult < Nightmare < Hell < [Tyron Odin]”

- Description from Novelupdates

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.

Callius von Jervain.

A character who dies no matter what he does. A character who falls into a forced choice route where he can only die, no matter his choices up to that point. However, there is a single route where the character can live and play the game.

And I have to carve out that route somehow.

Because I’ve become Callius von Jervain in the game.

Zend Wolfled, a fallen nobleman known to the world as the most hated man in the world. And the main villain in a famous romantic fantasy novel.He was feared and hated because of what Zend had done so far without knowing what caused Zend to do these things.Zend has a secret that the world doesn't know that he is a Reincarnator and Tranmigrator. Zend knows that he is a villain character from a romantic fantasy novel, but he lives on his own terms.In the end, Zend only lived as a name labeled a villain by the whole world.Until the day comes, Zend was the last human to survive the appearance of The Evil One.The Evil One and The Angel saw the potential in Zend and sent Zend back to time Zend younger, second change-In this life, Zend will be the hero and villain of this romantic novel once again. Zend will engage with this entire world. Meet Transmigration, Reincarnated, 7 Sins, 12 Color, 6 disaster and Apostle.Zend Wolfled regret, hatred, anger, sadness and revenge will begin once again...