That Unique Monster Who Just Got the 'Consciousness' Passive Skill - Chapter 45: Lucky

While returning home from a boring day of work, a black hole opened up in front of John and sucked him in. Before he was floating in the blackhole, a helmet latched on to him. "Uploading A.I under progress...Activating Survival Kit" A weird robotic sound appeared within the conscious of John and suddenly a white energy enveloped him... After opening his eyes, John noticed he was teleported to a whole new world. A world of magic and he was a user of a system. Arkon, the world John was brought too, was a medieval world which is 10 times bigger than earth. This new world held many new mysteries and this was the beginning of John's adventure. John will dominate and stir the world with his new system. Old technologies begone and use my advanced techys instead! Ha! you want to hold a politic, economical and military war with me? Sorry but my system is too broken for you all to counter.

After getting betrayed and killed by the only person she’d loved, Miss Shang wakes up in the body of the cowardly crown prince Shang Wuxin, who, due to her own circumstances, was actually a girl cross-dressing as a boy. After inheriting the crown prince’s memories, Shang Wuxin has three things on her agenda:

1. Clean up the house

2. Gather loyal followers and soldiers

3. Get the throne

- Description from Novelupdates

On her wedding night, framed for infidelity and to be burnt alive?Chu Qianli laughed heartlessly, “I've already written the divorce letter for you, farewell.”Feng Yexuan seized her firmly, his cold and sinister voice cutting through the air, “Thinking of leaving? The only way out is over my dead body!”…The Divine Doctor unexpectedly transmigrated into the unlearned Princess of Prince Xuan, and Chu Qianli only wanted to live an easy life without any ambitions.But she inadvertently caught the attention of the obsessive and insane Prince Xuan and accidentally got spoiled to the heavens!One day.The officials approached with gloomy faces, “Prince, the Princess is causing chaos in the Golden Hall again, please reassert your authority!”Feng Yexuan knelt before his wife with a thud, presenting a “taming husband whip” with both hands, “Lili, I've ripped their mouths for you, can you be a little gentler?”

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.