In Naruto as Zhongli - Chapter 99: INAZ - 97

Kujo Yuuri, who had been playing Elysia Online, finally changed her occupation to the sage of her desire. Then, she was asked whether to go to the true Elyasia or not and selected [Yes], and somehow went to another world. Furthermore, she became a small child.

The small sage Yuuri and her companions’ love and adventure fantasy.

“If I don’t die… I swear I will act on all my evil thoughts..”

Not exactly everyone’s typical thought when they’re about to die. What will a cowardly young man do when reincarnated with the evil powers to redefine his destiny? Can the natural kindness of human nature triumph over evil? Will he become the cold-blooded demon king of legend, or will he forge his own path and rain down another kind of terror?

- 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.

In his past life, as the countdown in his mind reached zero, people discovered they could enter and exit a virtual game at will. Inside, they could fight monsters and level up. Like most, Ye Qiu didn’t pay much attention to it and became a casual player, only logging in occasionally.But ten days later, the game suddenly shut down. And then, it merged with the real world!Monsters began to rampage, demons started to roam freely! Along with them came levels, equipment, skills, pets…And Ye Qiu, at the moment the server closed, was only level 5!From then on, he could only struggle to survive, hiding and fleeing, even enduring humiliation and ab*se!Until his final breath, he remained unknown, weak, and pitiful!In this life, Ye Qiu has returned to twenty years ago. And the game has just launched…