Rebirth: I Will Win Easily in the Apocalypse - Chapter 10 - 6 Marriage Proposal and Registration_2

Imagine being forced to live, after death, as incorporeal bodies trapped in a vast space of nothingness for thousands of years, with nothing to do but exchanging past memories with other cohabitants (read: weirdos). Everybody wanted out, but there was no way to leave the Void…

In the Celestial Empire, a land ruled by Immortals and stalked by Spirits and Beasts, a young girl from the slums of an unimportant city is found to have the Talent. In the great Sect of Argent Peak, she will take her first unsteady steps upon the way.

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.

[R18 novel with a lot of sexual content]Artem never expected to take on the role of a villain, let alone transmigrate between harem novels. Bound by a system, his task is clear: steal the heroines from all the protagonists’. From Chinese Cultivation and Korean Gate to Japanese Isekai Fantasy, VRMMORPG, and beyond—no heroine is off-limits, and no protagonist is safe!