MTL - The Twelve Zodiac Guardian Gods - Chapter 2 Perfect tattoo (below)

In a world where mysticism and steam industry coexist, cursed objects, the Reception Bureau, and Evil God fanatics...That year, the King was bedridden with illness, the successor was inexperienced, and power slipped away, leaving the empire teetering.That year, external forces gathered around the empire, and foreign civilizations eyed it covetously.That year, the prophet delivered a prophecy that the era of civilization was nearing its end.That year, Ethan arrived at a small town on the outskirts of the imperial capital. To survive in this perilous era, he began practicing Fireball Skill.Years later, Ethan looked at the meteor falling from the clouds and realized there was a problem.The beginner Magic he learned seemed a bit off.

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.

In the foreign world, the martial artists dominate the world and the sword of the emperor controls the fate of hundreds of millions of lives! Long Yu, the number one killer on Earth, after dying, takes rebirth in this new world in an aristocratic family of martial artists but faces rejection because he is unable to practice martial arts.

- Description from Novelupdates

Her step-sister just died three months ago. Now, she insists on marrying Chu Lui, who is supposed to be her future brother-in-law, the mind behind the Chu Enterprise. The world is sure that she, the new bride-to-be, had caused her step-sister’s death in order to seduce him.