Fortunately, I Met You - Chapter 169: No title

Julian Weber is an officer in the U.S. Army Corps of Engineers and a graduate of Westpoint Military Academy with a degree in civil engineering. As U.S. involvement in Afghanistan comes to an end, Lt. Julian Weber finds himself involved in a terrorist attack by the Taliban, which claims his life.

However, he quickly finds out that death is not always final as he is reincarnated into the body of a Baron’s son and heir in an alternate Earth set in Late-Medieval Europe. In an era of political turmoil and civil strife, the Baron’s young son is named Regent of the Barony of Kufstein and forced to contend with feudal powers. Will he be able to institute reforms leading his Barony into the age of industry?

Or will he succumb to the pressure of his feudal overlords and a corrupt church that seek dominion overall?

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.

[Trait: Protagonist's Desire][Acquire one trait possessed by the protagonist you reincarnate into.]A killer physique, a hypnosis app, becoming a shota...The protagonist has gained the ability to reincarnate into characters from adult games and make their traits his own. NO NTRRomance | Fantasy | Harem | Multiverse | SMUT | R18 | Reincarnation | NTL

A striking man of mysterious origin and peerless talent, he looks back at the world, in all its entirety, with utter disdain. And yet, in the treacherous and unpredictable ultimate formation of the Boundless Secular World, he guards a breathtaking ancient qin with broken strings, waiting silently for the destined one to arrive!

A boy encounters him, and knows for the first time that the world beneath the Heavens is a fickle place. Not even demons, devils, ghosts and monsters can match the frivolity of human nature!

A slender physique, and jade-like beauty, but the sword that strikes between heaven and earth is not unlike a streaming rainbow!

The vastness of the starry sky, the seven emotions and six desires! Greed, anger and ignorance! The teachings of Buddha will grant you boundless strength!

A sea of blood will come, at the cost of all mortal beings full of honest hope!

The ghosts wail as the gods roar, but the sea of blood has no end!

Where, pray tell, is the path I should take?

Since there is no path, no matter how bitter and bloody the sea, even if my boat is made out of bones, I will soar to the heavens above!

- Description from Novelupdates