Unserious Beast Tamer - Chapter 414 - 255: Shopping, Sound Recording Conch_1

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.

Killed by a Sage Emperor and reborn as his 13 year old self, Nie Li was given a second chance at life. A second chance to change everything and save his loved ones and his beloved city. He shall once again battle with the Sage Emperor to avenge his death and those of his beloved . With the vast knowledge of hundred years of life he accumulated in his previous life, wielding the strongest demon spirits, he shall reach the pinnacle of Martial Arts.

Transmigrated to a wizarding world.'But... what about the promise of wizards pursuing truth?''Why is it just a bunch of greedy people who seek power!'...Passing guests, please come in and take a look; if it's not the right fit, then feel free to leave.

Shoved into the backseat of his father's car right after graduation, Riley Hale ended up marching toward a company building with a bagged lunch and a pen.Still in his toga, the fresh graduate never thought he’d land in the office of the continent’s top lizard, err, dragon, as his aide.And that would’ve driven any person wishing for a corporate career to tears. After all, who wouldn’t want to serve the fastest ticket up the corporate ladder: Kael Dravaryn, the infamously elegant, unhinged, and extremely overpowered Dragon Lord of the continent?Well, that would be Riley.The same Riley who didn’t expect to spend his days dodging fireballs, dressing his boss in robes more complicated than dark magic, and serving as a literal target during morning sparring.Now trapped in a job he never truly agreed to, the hardworking aide decided to hold out until it was time for his glorious resignation. But leaving a dragon’s clutches could never be easy, especially one with elemental mastery and a finger worth a private army.Yet, as Riley, who longs to quit, attempts to navigate ancient politics, wyvern threats, and other accidents (many of which are definitely not his fault), he might just hallucinate himself into seeing something beneath his boss’s arrogance and molten glares.Maybe he’d actually care if Riley got turned to ash.