A Peacock Husband of Five Princesses by day, a Noble Assassin by Night - Chapter 84 : Stealing the chest

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.

I reincarnated as a lizard in a martial arts world.“Roar!”“He’s using the lion’s roar!”“To deflect the Ten-Star Power Plum Blossom Sword Technique! Truly indestructible as they say!”“This is… the Heavenly Demon Overlord Technique! It’s a Heavenly Demon, the Heavenly Demon has appeared!”It seems they’re mistaking me for something else.

Pinnacle of martial, mountain shifting and sea filling, catching stars and seizing the moon, reverse the flow of time!

Extremity of the sword, one sword to form the dao, one sword to reach the immortals, one sword to break the laws!

The young Li Fuchen, chanced upon the Golden Talisman which allowed his spirit soul to constantly evolve. In this world where prodigies and experts were everywhere, he used the sword in his hand to ascend to the absolute pinnacle.

The world will decay one day, but my reverence shall be eternal.

- Description from Novelupdates