MTL - One Piece: Wudang Baiye, Deputy Captain of the Straw Hats - Chapter 408

An incredibly athletic older brother, Tenryu Taiga. A programming genius girl, Tenryu Fuyuki. The two siblings separated for eight years ended up living under one roof again after facing the problem – a lack of funds for living expenses.

Fuyuki proposes a way to earn money, a core system deeply involved in people’s daily lives, a game that awards you money as a prize for defeating malicious bugs in cyber world, the 《Aries》structure. Taiga after becoming a warrior in the game relying on his inborn senses, is puzzled by the unfamiliar sensation.

One day Saionji Rui, Fuyuki’s best friend appears and is attacked by a mysterious bug― “I’ll be waiting, my prince.”. Hybrid fantasy battle of cheating siblings begins here!

Lacking a pocket dimension, lacking a power, lacking a thigh to hug onto and the three life advantages (money, power, and looks), he had been cautiously living in the apocalypse for ten years, getting closer to falling inside the zombie’s mouths. But unexpectedly, he had the terrible luck, to be caught in a fight between two gangs and die, it really left people feeling disappointed.

Arthur Ventrike, a genius second-year at the prestigious Wolkan Royal Academy, hailed to be the most talented in his generation, reaches the Swordsman stage of Knight at just 15 under Grandmaster Thorne Bladesong. But envy strikes when a fifth-year student tries to poison him. Though the plot fails, Arthur is left crippled, his dreams shattered. Just when all hope seems lost, he inherits a Great Sage’s legacy and sets out to become the greatest wizard along with the blessing of an indecent goddess and save the world from an ancient evil.

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.