Elf Tensei Kara no Cheat Kenkoku-ki - Chapter 8Book 3: -3: Maple Syrup

Immortals, gods, demons, princes and generals; dragon girls hold lamps, and the cups hold the sea.

Wild foxes practice Zen, and fierce tigers realize Taoism; they swim in the North Sea in the morning, and go to Cangwu in the evening.

Immortals and gods survive, and demons establish a country.

These originally had nothing to do with Qi Wuhuo.

And Qi Wuhuo, who always saw square characters in his dreams, only thought about being able to participate in the spring test in the coming year.

Until when he was making yellow rice rice, an old man gave him a jade pillow, which made him have a long dream.

Huang Liang has a dream.

…………

Huang Liang awakened from his dream and broke his heart, and since then he has opened the door to practice.

The golden crow flies, and the jade rabbit leaves.

One grain of millet in the three realms, the dust of the mountains and rivers for several years.

Pass the sword leisurely through the downtown.

No one knows that I am a real fairy.

- Description from novelbuddy

Riku Barusak is a hard-working child. Despite possessing an innate superior physical strength and having withstood harsh training she fails to unlock her talent as a spiritualist. The failure results in her being thrown away by her family.

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.

A man betrayed by a comrade dies a wretched death as a third rate swordsman. His existence, his life, his emotions are all a nuisance in the eyes of society. But wait… What’s this green skin? Reincarnated as a goblin? Wait, I went back in time as well?