After Divorce, Hidden Marriage Husband Became Addicted to Me - Chapter 618 - 384: _2

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.

Logan Mercer, an orphan barely surviving on his own, awakened the Spending System as a child.But as a broke teenager struggling to even pay his rent, how could he possibly use it?Bullied by his classmates and cast aside by society, Logan’s life changed the day he was suddenly surrounded by men in black suits.“Your father has been missing for over a year. As per his will, you are to inherit all his assets,” they said.To his shock, Logan learns that he was the sole heir of the Mercer family fortune — and with it came control of major businesses, unimaginable wealth... and the constant threat of his father’s competitors.“System, redeem one billion dollars,” Logan said.[Redeeming One Billion USD...][Congratulations! Your E-rank fire affinity has evolved into SSS-rank Phoenix Flame Affinity!]Now blessed with talent and wealth, all that's left is training relentlessly, growing his core, and unlocking even more different affinities within it.Follow along as Logan uses wealth and determination to rewrite his fate and grow stronger than anyone ever imagined.

“National Immortal Cultivation World” is an immortal cultivation game that once exploded on Blue Star.

But in the past ten years, a large number of players have retreated and abandoned the pit, and the game has been shut down.

Qin Mu is the only one left to sign in every day to get experience, do quests and dungeons, and plunder resources…

For ten years, Qin Mu has occupied the first place in all the rankings, and his level has also reached the first place in the entire server.

“What a great game, it’s a pity it’s closed.”

When Qin Mu was depressed, he found that the game world suddenly became reality!

There are swordsmen flying with their swords, and their sword qi has broken thousands of miles; there are magic cultivators who violate the law and disobey discipline, and separate one side; there are immortals who set up sects and create their own fire; Qin Mu sees himself, the immortal emperor is complete…

But he found that the most troublesome thing was that all the Dao Companions he got married in the game were all realized.

Not only that, the dungeon quests he cleared in the game, the bosses he fought, and the female NPCs he stalked all came to life. The most terrible thing is that the system also exposed his identity as an Immortal Emperor!

- Description from novelbuddy