Local Netizen Elf's Life In Another World - Case 16: Gungnir.

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?

Zhao Feng works hard to prove himself better than peers in the Martial Arts Training Ground, but just when he's about to give up, a mysterious black, marble-like, object fuses with his left eye, granting him the powers of the ancient gods.With his newfound powers, Zhao Feng embarks on the journey toward becoming the greatest martial artist of all time.

God's Seal Cathedra Rex, Part Two!Two sons of the dragon, each different; a genius elder brother and a good-for-nothing younger brother, who despite being identical twins, are worlds apart. However, they share an identical desire for peace. On the night of their birth, the moon was high in the sky.