Overpowered Archmage Doesn't Hide His Talent - Chapter 198:

Within the popular VRMMORPG «New Genesis», there was a ranker by the name of Arthur Holmes, commonly known by his in-game alias «Merlin».

While on a school field trip in the Czech Republic, Kang Hyuk happens to stumble into a shop called “Archmage.” To his disbelief, the shop is actually owned by an archmage… from another world! Forced to become the Archmage’s disciple, Kang Hyuk is punted into the Kallian Continent, where might and magic overwhelm and wyverns fly high in the sky…

In this world, people are either sword-wielding knights, magic-wielding mages, or spirit-wielding summoners. There hasn’t been anyone yet who can do all three… until now.

He always told me that he dreamed of me at night.

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.