Doomsday Descends: My Villainous Destiny - Chapter 15: Doomsday Arrival, Awakening of Talent!

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.

Crossing to One Piece world, he became Roger’s younger brother.

Unexpectedly, Gol-D-Roger who was in his fifties had a teenage brother. But he was so weak.

Fortunately, at the age of sixteen, he actually found himself with a possession soul system.

He had attached to the master IP man, also to the White Phoenix and to Ge Nie with his strong ability of the Hundred Step Flying Sword.

If you think that he can only Purchase these? Then you’re wrong!

Pain, Itachi, Ichigo Kurosaki, as long as there is money, any soul can be Purchased.

- Description from Novelupdates

A mortal teenager strayed into the immortal way because of an accident, struggling on the road of seeking immortality.

Immortal Road is difficult to climb to the sky, in the face of numerous obstacles, his desire to seek the truth is still unabated.

Looking back again, the green mountains are still there, so the old is boneless.

- Description from novelbuddy

In a time when the Divine Prefectures of the East Sea were in great disarray, Emperor Ye Qing and Donghuang the Great appeared to save the day. Under their rule, the prefectures united and all nations as well as their kings have been controlled. However, the legend of these two great heroes becomes altered when Emperor Ye Qing’s name is wiped from the history books after his sudden death. All statues and images of him were destroyed and his name a taboo. Only the legend of Donghuang the Great shall live on.

Fifteen years later, a young man by the name of Ye Futian begins his journey in search for his true identity. The legend of Futian was going to be one for the history books.