Life in North America, you call this an autopsy officer?! - Chapter 479 - 272: Future Development, Establishment of Umbrella Company

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.

One night she gets drunk and mistakes the most well-known Mafia boss for a Host* and intends to sleep with him.

Karl Adelheit, a self-proclaimed ordinary student returning from military service.

And a nobleman who enlisted as a soldier and received Medals of Honor.

Synopsis: Tags: [Game-World Crossover] + [Sovereignty Farming] + [Luck Mastery] + [Undead Scourge] + [Inter-Species Conflict] + [Heroic Battles]This is a world where games have invaded reality.Every year, students turning 18 awaken to a job change.One person crossed over and became a Necromancer.Relying on a luck-based talent that made wishes come true and a legacy from Mother Earth, this person rapidly gained power.While others gambled on skill mutations, summoning variations, and the chance with endless resources,he simply needed to shake his talent and use the least resources to obtain everything.With an undead frenzy, he broke through the blockades of the other nations on Blue Star, making his empire great again.With the undead scourge, he wiped out the decayed porcine dynasties within realm territories and became the new Realm Master.In the name of the Dead Spirit Overlord, he waged war on the Battlefield of Ten Thousand Tribes and ascended to the throne of the Demon God.