Everyone is Young Except for Me - Chapter 311

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 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.

She was dressed in white, with a mysterious orchid imprint on her forehead, her skin like jade is always covered with a veil. Since childhood, she had left her parents due to her special status and lived her life with her master in the clouds. She was not yet ten when her medicinal skills were renowned in the world. In order to save the people, she descended the mountains, however, she encountered a storm on the way to the epidemic area. The man who saved her would tease her for enjoyment, little did they know…

“Darling, I love you…” He was the heir to the consortium and she had just divorced. The day she was divorced, she was kidnapped and forced to be the doctor in charge of his case. To add insult to injury, this man would sleepwalk to her bed every two to three days… another headache!