Steadily becoming a saint, the immortal officials hired me to tend the horses - Chapter 639 - 632: The Fortune of the Immortal Emperor’s Eye

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.

Chen Shiping, a Qi training monk from the Foundation Establishment family, is struggling in the world of cultivating immortals

- Description from novelbuddy

A man is reborn into the world of Avatar: The Last Air Bender as a waterbender from Katara's tribe. Best of all, he was the same age as her, and he had a system with him to help.He knows the future and a system that lets him continuously get stronger by completing quests or long-term missions, as well as giving him the ability to copy abilities from others for himself. He will become invincible in the world of Avatar, even more so than the Avatar himself.

The ninth son of the Tianhan Immortal Emperor of the fairy realm, Qin Yun had the rare gift of the Chaos Immortal physique and even achieved the cultivation level of Real Immortal at ten years old. He was so skilled that his father was considering making him the successor to the throne.

But his idyllic life was shattered at the hands of a massive conspiracy, and the Immortal Emperor, his own father, not only exiled his mother to endless torture in an unfathomable abyss, but he also sealed away Qin Yun’s intelligence and memories away and banished him to the mortal world.

Stuck on Earth as a helpless child, he is taken in by a beautiful woman in a small town who adopts him as her younger brother. Things are fine for a while, but when a bully attempts to extort his newfound sister for sex, and no one is willing to stand up to him because of his powerful friends, can Qin Yun tap into his old skills to protect her?