MTL - Serious People, Who is Learning Magic at Marvel? - Chapter 1 Breaking the world

Whenever our ship encounters a tenth-level storm, my comrades-in-arms will not have the slightest worry, because they know that I still have me on board.

- Description from Uukanshu

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.

Escaping from the wedding she dreaded with Crown Prince, Aed Ruad, Princess Anastasia ended up becoming the captive of the Lore's most dangerous man, Prince Ileus.

As 21 years old Noah closes his eyes for what he thinks will be eternity, he wakes up in the body of a girl 7 years younger than him.Vasilisa, as she is known, is hated and mistreated by the people around her because of the Muddy Tongue curse which not only impedes her speech, but makes her magic unstable.This effectively makes her the harder than hard mode when it comes to reincarnation, and, of course, fate made her his “avatar” in this new world full of mechanics he only ever saw in video games.Despite this, Noah as decided…Whether as Vasilisa or himself, this time he will find a way to exist for the world.