Death Guns In Another World - Chapter 583 - 546: Breakfast with the Mayor

Before his death, he was the only sword cultivator in the whole world, who dedicated his entire life to the path of sword immortality.

When he opened his eyes again, the world had completely changed. He began to cultivate the path of sword immortality again, slaying the heavenly way, shattering the universe with his will, and achieving the realm of sword immortality!

- Description from Novelupdates

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.

Encountering a car crash, the King of Silver Screen, Ye Sinian, was bound to a Cannon Fodder Counterattack System.

After reincarnating for hundreds of lives, he has finally earned enough “travel expenses” to go back home.

However, he didn’t think that the system would suddenly malfunction, making returning back home from then on hopeless.

With the shackles of a millennium broken, Ye Sinian aggressively counterattacked!

Reversing fates while hugging the mentally ill* Lord Seme, he walked towards the apex of humanity!

*Mentally ill – Schizophrenic

- Description from Novelupdates

Jiang Chen had unexpectedly found himself thrust into a world of cultivation, stepping into the role of a core disciple within a famed sect. Fated to be the villain, his future loomed with calamity. He had plotted against the protagonist, crippling his dantian and leaving him a disgraced outcast teetering on the edge of expulsion. Were it not for an unexpected twist, Jiang Chen’s part might have ended as a mere footnote in the protagonist’s glorious tale. Fully aware of his precarious position, Jiang Chen’s lips curled into a sly grin. Alone, he mused: ’Is the protagonist powerful? Without a doubt.’ ’But will I tremble in fear? Absolutely not.’ ’Why? Because I have the Immortal Great Villain System!’ ’Wait... there’s more than one protagonist?’ ’Well, isn’t that just perfect?’ With a determined glint in his eyes, Jiang Chen declared to himself, ’As the ultimate Great Villain, I will defy the will of Heaven and seize my place at the summit!’