The Reincarnated Vampire Wants an Afternoon Nap - Chapter 105

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.

Gabe King starts college desperate to change—to make friends, find love, and finally bury the twisted obsession he’s secretly held for his mother. But one drunken night at a party shatters everything. Inexperienced and overwhelmed, he accidentally cums inside a hooker… only to realize it’s his Mom, Angela.She doesn’t recoil. She smiles.For Angela, this is permission. The moment she’s waited for. Her yandere love for Gabe, once hidden beneath motherly concern, is now unleashed. And she’ll do anything to keep him, sabotaging his friendships, crashing his classes, and reminding him that no one will ever love him like she does.More Plot than Porn.[Some NTR, but not from the mom]

Chen Rui, an otaku from earth, is reborn into a human body in another world, who falls into the legendary evil, brutal world of the devil called Mozu where humans are treated as food. He has to survive while facing horrors of the devil, violent dragons and a variety of power enemies depending on a strange super system chip and his wits. Surrounded by Devil’s beauties such as black-bellied lolita princess, cold queens, violent dragons, charming poisonous devils …

Wanting to live in the Devil’s world is hard! Wanting to live in the Devil’s world as a human is harder! Wanting a human to be the devil’s son-in-law is hardest!

Let us see how a small otaku uses power and strategy step by step starting from an ordinary human to writing a legend as the devil’s greatest son-in-law.

- Description from Novelupdates