Problematic Little Sister Fell In Love With Me - Chapter 490: The sealed memories

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.

What should I do if I cross to another world and become an NPC?

This idea has been deeply rooted and sprouted in William’s mind!

Therefore, he decided:

I want to be the strongest NPC in history.

Wear the thickest armour and give the most vicious beatings!

Who says an NPC will be killed by players?

Who says an NPC upgrades more slowly than players?

Who says an NPC must explode equipment, I can explode in more ways… Bah humph.

Anyway, it’s impossible for me to die. Just take a look at all you trash players. Your father will stand here and let you chop for an hour without a frown!

- Description from Novelupdates

Lucas is a homeless teenager who had everything taken away from him— his family, his home, his childhood. Even worse, he was born without any abilities in a world where humans with superpowers dominate.

All of that would change when a new dungeon appears before Lucas.

Thinking that it was a sign the gods have given him— that he should just give up and end himself, Lucas enters this dungeon without hesitation while expecting death.

However, inside the dungeon was not the end like Lucas had expected.

Instead, it was the beginning of his life of carnage.

Wielding the power of a «Hero», Lucas begins his journey of vengeance on the world that stole everything from him.

Before her rebirth, she was abandoned by her parents, then murdered by her seemingly pure but vile younger sister. After her rebirth, she kicked all her scum boyfriends to the curb and began a campaign of abuse against the superficially perfect. Rumors were rife on the internet that Qin Sheng was a kept woman? A bunch of computer nerds, "Let's hack the keyboard warriors' computers." The first director, "Boss, have you written the script yet?" The medical expert, "Sheng Sheng, our research institute will give you 100 million. When will you be able to join our team?" A famous painter, "Sister Sheng, take me along when you hold your art exhibition." The CEO of a billion-dollar company, "Boss, when are you going to publicly disclose your identity?" Finally, a big boss pulled Qin Sheng into his arms. "Sheng Sheng, I've transferred all the assets under my name to you." Netizens, "?? This world has suddenly become crazy?" She was a business genius, a computer genius, a legendary screenwriter, a legendary painter, and a legendary medical expert. It remained to be seen how she would create flourishing prosperity. (The male protagonist has a propensity for recognizing bitches, but is infinitely sweet and doting to the female protagonist!)