The First Cultivator - Changing Existence - Chapter 47: We Are Not The Same -

One day, in front of my eyes appeared a silver-haired Goddess.

What kind of bullsh*t is this woman spouting?

“…What?”

No, I’m not.

Li Xiaofei, thrust 500 years into the future, finds himself as a young orphaned man in a harsh, post-apocalyptic world. Raised by a woman only slightly older than himself in the unforgiving slums, he quickly learns that survival requires both strength and cunning.In a world ravaged by alien star beasts, where gangs rule the streets and political factions vie for control, chaos is the order of the day. Amidst this turmoil, Li Xiaofei must carve out his own destiny. Armed with the mysterious Moonlight Treasure Box, he embarks on a perilous journey to make a name for himself and protect the ones he loves.Will Li Xiaofei rise above the chaos to bring peace to his world, or will he be consumed by the darkness that surrounds him?Official BlurbThe star beasts invaded, and Earth’s civilization collapsed. A young man, wielding the artifact Moonlight Treasure Box, drew upon the legacy of three thousand martial arts techniques from various worlds. He protected humanity, won the hearts of beautiful women, slew star beasts, suppressed myriad races, ruled the universe, and commanded the heavens. In the vast cosmos, he was invincible!

[You can now choose three of the following seven options
1. Go back to five years ago with the present memory
2. Five centimeters taller
3. Seven million deposits
4. Appearance +50 points
5. A company with a market capitalization of 500 million
6. Proficient in a foreign language
7. Teaser live broadcast 10 million virtual coins]

Li Ang became angry after finishing the selection: choose every day, choose, choose, you will give it after the selection!
…
Fuck, it’s really shipped!

- Description from novelbuddy

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.