Reborn as the Blissful Wife in the countryside - Chapter 8 - 00: Kill Them

Transmigrate to the world of One Piece, reincarnate as Saint Imu; Control the world government and sit on the throne of the void.He obtains the star map of the omniverse and contemplates the sea of dimensions.Gather all individual combat power, military power, financial resources and all material resources to open the star gate, conquer all dimensions, and break the limit of individual power!Unite or be destroyed, how to choose?

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 journey of a generation’s male empress started because of four words.

“Send a dowry escort.”

During the 19th year of Yuanqing, Qi Yunruo boarded a carriage and entered through a corner door of the second prince’s estate. Then, across the watery corridor, he gazed at the prince from afar.

Notes:

For aristocratic women in imperial China to marry into a family part of the upper nobility, they must be of the legitimate line and must also have an escort/dowry maid that married into that family. That escort would be a “ying” (媵) and could be considered a concubine.

- Description from Novelupdates

Jun Xie was the number one assassin in modern earth. His skills and knowledge in the field of assassination were unparalleled, his accomplishments unprecedented, his reputation terrified the entire underworld. However, during a mission to retrieve a mystical treasure, a mishap occurred…

He is now Jun Moxie, a sixteen year old super level debauchee, sole heir to the declining Jun family. A family of valiant heroes, left with an old grandpa, a crippled uncle and a debauchee as the sole heir! Accepting the world’s criticism and cold stares with a smile, his new journey begins! His life will be carved by his own will! Rise to the top! Evil Monarch Jun Xie!

“This cup I toast to those I’ve killed in my past life. Forgive me, for there is no chance for you to have revenge. Gulp!

This cup I toast to those whose life I will take in my new life. Forgive me, for you are fated to die by my hands. Cheers!”