Shikkaku Mon no Saikyou Kenja~ Sekai Saikyou no Kenja ga Sarani Tsuyoku Naru Tameni Tenseishimashita~ - Chapter 280: Strongest Sage, Challenges Experiment

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.

Xiao Xin, a Pokémon’s diehard powder, accidentally succumbed to death while using the game modifier, the soul passed through the Pokémon world, a child who accidentally swallowed a lightning stone in thunderstorms and was strangled by lightning.

On the body, the most important and most important, he also brought his props backpack in the game…

- Description from Qidian

Actress Chu Yaoyao was murdered. But she woke up, 20 years later in her timeline, in the body of a notorious 18th-line female star with the same name as her.

A scumbag wants to ban her? The little assistant wants to step on her and take over her fame? The patriarchal family wants to suck her dry? Netizens organized a group to hack her? The most frightening thing is that her figure is out of shape, beyond recognition!

With the Film Empress holding an interstellar red envelope group, none of these are problems.

The bigwigs in the interstellar entertainment industry give out red envelopes every day. As her fans, they only ask the Film Empress to guide their acting skills.

The first step is to lose weight and become beautiful. The second step is to become popular in acting. The third step is to abuse the scum and slap the face. The fourth step is that it’s not bad to fall in love…

The actor next door, what do you think about falling in love?

- Description from Novelupdates

Carlos Valois thought dying once was enough—until he woke up as a 10-year-old in the world of “The Dark Era,” a game he'd mastered in his previous life.Born as the last heir of a fallen noble house, Carlos discovers he's destined for a tragic fate: in six years, he'll be manipulated into joining the dark forces and killed by his own childhood friend. But this time, he has the ultimate cheat code—memories of the future.While other kids play with toys, Carlos hunts for divine legacies. Using his game knowledge, he performs an ancient ritual and steals a Demigod Mark from the thousand-year Sacred Oak—a power that should have remained hidden for decades.At 15, Carlos awakens as a Death Herald with broken stats that shouldn't be possible. Most Death Heralds are fragile summoners hiding behind weak skeletons. But Carlos combines his necromancy with stolen divine abilities, creating a hybrid build that turns him into an unstoppable force......[Skeleton Warrior has successfully evolved into Purple Thornblade Skeleton Guard!][Purple Thornblade Skeleton Guard has activated Bond: Glory of the Purple Thornblades!][Twelve Purple Thornblade Guards have formed an Undead Armored Knight Legion!].....His skeleton warriors aren't cannon fodder—they're elite undead legions enhanced beyond normal limits through secret evolution paths that took thousands of players years to discover.Every “coincidental” encounter is actually Carlos farming legendary opportunities. While his sister thinks he's just a lucky genius, Carlos systematically raids every hidden treasure, secret technique, and forgotten legacy he remembers from the game. Ancient bloodlines, divine artifacts, mystical cultivation methods—if it exists, he's taking it.With his infinitely evolving undead legion, Carlos set out on a path to rewrite destiny and become the supreme Death Herald legend.