Monarch of Evernight - Chapter 1490

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.

The daughter of a duke, the stuttering Maximilian, married a knight of lowly status at her father’s coercion.

After their first night, her husband departed for an expedition without another word.

He comes back three years later, this time as a famous knight in the whole continent.

How would Maximilian face him on his return?

Ever since He Mulan, a 28 year old forensic investigator, transmigrated into the post-army civilian Hua Mulan’s body, she’s been under a lot of pressure. Unlike the folktale ending, there are no flowers or applause to be found here. After leaving the army and returning to her hometown, word by the countryside has painted the now 32 year old Hua Mulan as a homicidal maniac, an old hag, and a freak of nature, among other nasty things. Between piecing together Hua Mulan’s scattered memories, grappling with her fellow villagers’ prejudice against her, and fending off Mrs Hua’s attempts to match make her, He Mulan has her hands full. All He Mulan wants to do is protect Hua Mulan’s body till her soul comes back, but fate has other plans…

- Description from Novelupdates

He possessed the Xuan Gate Medical Arts and had fortuitously obtained a heaven-defying Spiritual Treasure!