Era of Galactic Elves: Starting with the Primordial Spirit of Enlightenment - Chapter 17 - The Power of the King - Mewsi!

One night she gets drunk and mistakes the most well-known Mafia boss for a host and intends to sleep with him.

Oh my! What should I do? It’s best to run away!

- Description from Novelupdates

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.

Many islands dotted the vast oceans of this world. However, some of the islands were a lot more sinister than the rest. Those islands, known as Nightmare Islands, were true nightmares to all but the strongest and most fortunate. Children were kidnapped and thrown on these isolated islands by the Nightmare Palace, forced to sign soul pacts with evil soul pets: Nightmares. These devils slowly devoured the souls of their trainers to grow stronger. If the children did not cultivate fast enough, their souls will be devoured whole, leaving only an empty husk behind.

Chu Mu, the protagonist, was an heir to the Chu Clan, but due to a plotted murder, he was thrown on the island, sentencing him to almost certain death. Dancing on the edge of life and death, he struggled to survive with a small Moonlight Fox he captured. When he finally escaped the devilish foremen on his island, he couldn’t help but let a breath out. But little does he know, the experience was only a beginning to a fated journey with his little Moonlight Fox…

#Expect a big Harem but MC won't mindless collect women on a whim. There's deep mature content. Beware!After getting rejected and humiliated by the very woman he's ever loved—and publicly dumped during lunch break in front of half the school while holding a giant teddy bear, blue roses, and a handwritten love letter titled “My Heart in .mp3”—Jayden Cross thought life couldn't get worse.Then he wakes up with a system talking in his ear.[Ding! Welcome to the Ultimate Copy and Paste System!][Function Unlocked: 10x Copy and Paste!]Now armed with a divine-level Ultimate System Jayden begins rebuilding his life with just copying and pasting everything and gets 10X more!What the world, the system, and the universe had shattered without remorse, only the Ultimate Copy and Paste System could restore. But it did not simply mend—it reimagined. It rewrote his broken existence into a force no storm could contain, only follow.