MTL - I Woke the Sick and Disabled Prince on Our Wedding Night - Chapter 459 planning

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.

The summer I was 17. A painting I created was sold. For 1.4 billion won.

I don’t want to die. I want to be free. To that end, I shall….reconcile myself to the fate of becoming a “monster”.

A strange disease that racks one’s entire body with intense never-ending pain, until the person slowly withers away and eventually dies. After a few years of braving through the pain, the boy is in no luxury to even feel despair. With nary a soul to tend to him, he breathes his last.

The next time he opened his eyes, the boy had become an “Undead” of the lowest rank through the power of an evil Necromancer.

The boy rejoices at having his earnest desire fulfilled, which is a body that will never feel pain. However, he realizes that he is still under someone’s control and how it was no different from when he was cooped up in the hospital ward.

But the world would not leave alone the boy who only wished for peace.

The Necromancer who revives the boy from the dead, names him “End” and attempts to gain control over him.

The Undead Knights, lay their lives on the line to persistently chase after and annihilate the beings of the darkness.

With countless monsters under their command, the Demon Lords rule over their own lands while they all contend for ultimate supremacy.

The motivation being survival and freedom. The requirements being caution and power.

This is the tale of the cowardly King of the Undead. In his pursuit for freedom, he heads into battle and turns tail at times. He knows when to fear his opponents and when to waver in his decisions.

A prestigious senior mechanical engineer in the industry, Xu Yi was sent to a world dominated by magic.

In a world with an almost non-existent industrial system, how can Xu Yi display his value?

When magic collides with modern technology, when magic merges with machinery, that is the beginning of this story.