MTL - From the Void King To the Ghost Swordsman of the Light of the Beginning - ~ New Book—The Secret Puppet Master in Death

Karl, a young man stuck in a rough patch after losing his job and burning through almost all his savings, wandered through the cold, dark streets of Eldoria. On the damp, silent sidewalks, he stumbled upon something bizarre: an old gacha machine mysteriously appearing at every corner he turned, almost as if it was following him. Driven by a mix of curiosity and the overwhelming weirdness of the situation, Karl finally gave in and used his last bit of money on the machine. From the gacha ball, he pulled out a card with a barcode.Back in his cramped apartment, curiosity finally won over caution, and Karl scanned the barcode. To his shock, an app called “Common Sense Manipulation App” installed itself on his phone, claiming it could alter people's “common sense.”------Support Me By Gifts or Power Stones-----

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.

“How did you board the Astral Express, walk the Path of the Stars?”“Because I ended the Honkai, altered everyone's fate.”“So your first step on this path was becoming a hero?”“No, it was for survival, searching for a thigh to cling to.”“And then?”Ryan adjusted his glasses, his voice resounding.“I became the thigh.”

The romantic comedy light novel series centers on the gaming lives of various high school students who play video games, including: Keita Amano, a lonely young man who loves video games; Karen Tendō, the beautiful president of the video game club; Chiaki Hoshinomori, who constantly fights with Keita; and Tasuku Uehara, who puts on a facade of being satisfied with his life in the real world, but he in truth loves video games.