Kujibiki Tokushou: Musou Hāremu ken - Chapter 234

I don’t know how to write an introduction. The few times I wrote it before, the more I wrote it, the more ugly it became. Let’s keep it simple:

This is a Marvel fan novel, with a little added Hong Kong manga elements, if you haven’t read Hong Kong manga, it won’t affect the reading experience.

- Description from novelbuddy

After catching his wife in bed with another man, Alex died of a heart attack—only to be reincarnated in another world with a MILF System in the frail body of Asher, a sickly teenager.Betrayed and furious for his wife's infidelity, he vows to punish unfaithful women and seize control in his new world. But there's one problem: in this world, women reign supreme over men, blessed with overwhelming strength by the goddess herself. Outmatched and underestimated, Asher refuses to accept his place at the bottom. With the MILF System at his side, he’ll do whatever it takes to shatter the hierarchy and claim absolute dominance—even if it means conquering every woman in his path until he reaches the heavens to claim the ultimate MILF herself: the goddess.But can he rise to power in a world where men are nothing more than playthings?Find out in this wild, boundary-pushing saga!Disclaimer: This book contains intense sexual content and themes of incest. Reader discretion is advised.

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 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