Naruto: Reborn as Orochimaru - Chapter 275

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.

In the vast and boundless continent Cangtu, there were ancient sects governing the Ten Old Domains, unworldly immortal clans beyond the Blue Sky, and primordial demon gods dominating the dark abyss that together created a great number of brilliant stories over the long course of the history.

In this very world, there was a boy, named Lin Xun, who embarked on his journey to the pinnacle of strength alone through cultivation and spiritual tattoo inscribing.

Escaping alone from the Mine Prison where he had been living since he was adopted by Master Lu, Lin Xun knew nothing about his identity but the little information his adopter, Master Lu, had told him. With two ancient spiritual tools Master Lu gave to him before the destruction of the Mine Prison, Lin Xun started his journey to Ziyao Empire, where he is supposed to find out the truth of his lost Spiritual Vessel and the person who slaughtered his family, leaving him orphaned.

Will he be able to unlock the mysteries of the two magic treasures, unveil the secrets of his identity and create a legend of his own?

You thought being reincarnated as an extra-side character was bad? Imagine being thrown into the body of a villain who is disowned by his own family and discarded by the author.

Scheming female assassin transmigrated to become the weak Eldest Miss, her story is wonderful and stunning, attracting peach flowers to blossom open. Cold calculating emperor? Genius bad crown prince? Insidious happy-go-lucky prince? Gentle physician? Ice-cold mystery male? Who is her true love? Haha, but she only eats, definitely will not take responsibility! Beautiful men be careful!

- Description from Novelupdates