Shota's Isekai NTR Adventure - Chapter 1711: More spirits

Majiatisi Lei En, the sole Descendant of the Heroes is the nightmare of his entire town.

The apprentice of a proud Warlock, Lei En works hard to learn his trade unknowingly causing mayhem for those around him.

So when he stood on the tower of the Supreme Wizard, shouting with a heroic flair:

”I want to be the greatest of the alchemist of the Shenji Continent!”

A resounding roar of, “Boos” from the townspeople was the only response he got.

- Description from Novelupdates

The male student, Fukai Nagamasa, ignores his studies for college entrance exams in favor of following the path to chuunibyou. As he fainted during night cramming session before the exams, he realized that he was transported to a parallel world as a feudal lord in the Sengoku Era. Not to mention that suddenly, he was marrying the sixth Demon King, Oda Nobunaga’s little sister, the one who was purported to be an unrivaled beauty?

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.

The story begins with the last day of Yggdrasil, a popular online game which is being quietly shut down. Our protagonist Momonga decides to stay in his beloved game until the last moment, so waits for the forced logout. Unexpectedly, the server does not shut down and Momonga is stuck in a skeleton avatar in another world. “The powerful Overlord” needs now to discover the new world and face the continuous challenges that arise.