She's a Passerby, But Can See the Protagonist's Halo - Chapter 79

Fang Ze traveled to the world of psychic forensics and activated the detection system.

Since then, the world has gained a crime-solving wizard. In just one year, Fang Ze became the captain of the police force.

Suspicious disappearance cases, corpse dismemberment cases without clues, heinous vampire cases…

With his keen judgment, Fang Ze relied on the assistance of the system to grow all the way.

With the passage of time, Fang Ze suddenly discovered that this world seems to be more than just a psychic forensic doctor…

- Description from novelbuddy

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.

Transcend to become the prince of Daxia, activate the Devil Emperor Summoning System, summon the powerhouses from other worlds, and fight for hegemony in the heavens!

If I were the Devil Emperor in the future, I would definitely let your blood stain the sky!

- Description from novelbuddy

In 'Only Wisdom Awakened,' the world bears the arrival of monstrous threats and the emergence of awakened individuals wielding extraordinary powers.Hans Richter, a young man burdened by the weight of debt he had to take to cover up his family's medical expenses, inherits the 'UNKNOWN' class {Knowledge Seeker} on the somber night of his eighteenth birthday.Unlike his peers, Hans's abilities stem from his relentless pursuit of knowledge, and his boundless imagination, unaffected by the limits set by the 'system' for others.As Hans navigates this perilous world, he grapples with moral dilemmas and confronts formidable adversaries, driven by his longing to once again see his loved ones and unveil the truth behind the catastrophic events that reshaped his world.