I Became the Tyrant of a Defense Game - Chapter 14:

She married a driver she just met. However, the last thing that had ever come to her expectation was that her bridegroom was no other than the most mysterious billionaire in the city. This marriage brought her baby twins. Thus, she worked harder to support this family. She was the queen of the entertainment circle. When she met the king who dominated the business world, she finally knew her husband’s true identity.

After getting shot, Lucas, a serial killer, reincarnated into the novel world as a tragic villain with the same name, Lucas Ciffer.

Lucas Ciffer was supposed to be the Holy Kingdom's successor to the throne, but his demonic appearance and the powers he possessed terrified the entire kingdom. A white-haired boy with red eyes and pale skin, together with his dark powers, got persecuted and exiled by his own family. Not to mention that in the future he was destined to die by the hand of the hero.

Lucas fell from holiness, and, with the serial killer's bloodlust and knowledge of the future, he decided to prove the world right.

Yes. I could be a villain; no, in fact, I WILL BE THE VILLAIN.

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.

“I will let you be on top from tonight, please don’t divorce me, darling!”-----Evelyn’s fairytale life shattered when a stranger stormed in, claiming to be the real daughter of the Wright family with proof. Her enviable privileges? Stripped away. Her spotless reputation? Tarnished. Her four-year engagement? Abruptly annulled.But the worst betrayal came from her once-loving father, all set to marry her off to settle a business score—with a man twice her age!Everyone in the circle attended this scandalous wedding, eager to witness the downfall of the supposed fake heiress. Yet, the climax was not what even Evelyn had anticipated!Zevian Reign, the nation’s richest tycoon, known for being every woman’s fantasy and the nightmare of all his rivals, made a dramatic entrance. His arrival stunned the guests, but his brazen wish was even more startling! He casually demanded to replace the groom and marry the beautiful bride.No one dared to challenge, nor did anyone have the guts to disobey him. They were left with no choice but to watch the wedding unfold.And it was Evelyn’s time to smirk, for she was now the devil’s wife. And all those who had ruined her, they would pay back in tenfold!++++[Excerpt]“Why would I ditch my husband for a loser?” Evelyn chuckled, crossing her arms defiantly. “He is better than him in all the aspects.” Her gaze drifted to her ex-fiancé nearby, and she continued with a smirk, “Actually, a lot better in bed.”As Annabelle’s face flushed with disdain, Evelyn patted her back and leaned in to deliver another slap. “So, good luck with licking my leftovers, dear step-sister. He's a perfect match for you.”