Skill Hunter -Kill Monsters, Acquire Skills, Ascend to the Highest Rank! - 215. Truth of the Trial

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.

“Take me in, I’ll do anything you want me to!”

In her previous life, Lu Man is sent to prison after being framed by her step-sister and an asshole. After being released from prison, the only thing that greets her is her mother’s tombstone. Seeing the as*hole and bit*h getting happily along together like one big family with her birth father and step-mother, she sets out to die together with the as*hole and her step-sister in fiery flames.

The moment she opens her eyes again, she finds herself back on the very day she was framed. Resolutely jumping out the window and climbing next door, she seeks refuge from the man occupying the room there. But who would have guessed that the man is the brilliant hunk she has always admired from afar in her past life?

She vows to rub her eyes clean and be more discerning of people. She wants to make everyone who owed her in the past to pay her back!

“Young Master Han, can you let me hug your other arm too?”
“Actually, I have one more, do you want it?”
“…”

- Description from Novelupdates

Noah Brown had a gift for fighting. Unfortunately punching things didn't pay the bills, at least until he died and an Eldritch god found his soul. The encounter led him to a new world, summoned by bloody cultists, with nothing but the shirt on his back, and a strange item in his system menu.

[???] : A source of infinite potential.

Perhaps he'd finally get to put his gifts to good use.

Pirate World, Before the Summit War.Sengoku: “In this war, the advantage is ours!”Vice Admiral Tsuru: “Can we really win?”Sengoku: “We will win.”As the Summit War begins, chaos erupts on the battlefield.Above Marineford.Suddenly, Will appears in the sky with his crew, overlooking the entire battlefield.Sengoku: “What exactly are you here for? Are you planning to help Whitebeard?”“Don’t misunderstand.”Will scans the battlefield, his gaze sweeping over the powerful figures present. A hint of excitement lingers in his tone.“I’m only here for one reason—to kill all of you. That’s it.”Sabaody Archipelago.Will watches the Celestial Dragons strutting arrogantly through the streets, their eyes filled with disdain for the world. He can’t help but frown.“These are no ordinary Celestial Dragons… This calls for a heavy punch!”...Without hesitation, he throws a devastating punch, obliterating a Celestial Dragon on the spot, crushing the surrounding Marines and CP agents with overwhelming force.The survivors turn to a trembling communications officer clutching a Den Den Mushi and scream in terror:“Hurry! Notify Marine Headquarters! Call for an Admiral!”