Isekai Maou to Shoukan Shoujo Dorei Majutsu - Volume 11 epilogue

Liu Zilang had a well-kept secret — he was a prodigy in competitive FPS eSports. His specialty? CSGO. He even entered the finals in the prestigious world tournament.

Fifty years ago, Dragon City transmigrated to the Other World. Alone in the world, they lifted the banner of Earth’s civilization and fought against the terrifying forces of the Other World.

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.

One day, Emperor Wu Ling discovered, every night he would become a stone, kept on the jewellery box of a lady, embarrassing beyond embarrassing.

One day, Zhao Jin Yu discovered, the stone on her jewellery box could actually speak! Awkward beyond awkward.

This stone had a malicious tongue, harsh, two-faced and indifferent, Zhao Jin Yu itched to throw it smashing it to pieces…, who knew one day, wanting to save herself she used it to block a sword, it really did shatter, she cried for a very long time.

Again one day, Zhao Jin Yu was drafted into the palace, she discovered unusually, the emperor was like this he had a malicious tongue, harsh, two-faced and indifferent…

- Description from Novelupdates