Fairy Tail: I Stole the Ryujin Jakka in My Sleepwalking - Chapter 18: FTRJ -

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.

A literal ‘red flag’ in a world that sees her as a threat.Excerpt:“You shouldn’t be here,” Zenon growled, his voice low, eyes dark with conflict as he leaned away.Elira looked up at him, lips parted and swollen. “Then why did you kiss me?”“I couldn’t resist you.” His arms tightened around her waist instead of letting go.“Then don’t,” she said, without breaking the gaze.“Remember, you asked for it.” Zenon’s eyes darkened with desire as his lips found the perfect spot on her neck.---Elira Shaw was never meant to shine.Born an omega to a once-respected Beta bloodline, she’s lived as a ghost in her uncle's home, the acting Beta of the Ashfang Pack.After her parents' mysterious deaths when she was thirteen, Elira became little more than a servant to her aunt and cousin, Regina, the flawless Luna-to-be, groomed to marry one of the Alpha's sons.With no rank, no power, and no name worth remembering, Elira has long accepted her fate.But her fate transforms on her 18th birthday — the night of the grand mating ceremony.Not one, but the wolves of all three of Alpha Cyprus Ashford’s sons recognize her as their mate.The pack erupts into chaos. Regina's engagement plans crumble in fury. And Elira, the despised orphan, is suddenly the most important wolf alive.

“I, Lethia Ashcroft, accept your rejection, soon-to-be Clown Alpha of the Rotten Obsidian Pack, as my ungrateful mate. May your divorced life find its hellhole.”*****Year 2666.Werewolves and their kin have long embraced civilization, seamlessly blending into the high-tech world alongside humans.It is the year Lykon Haven hosts its once-in-seven-year event to select a new leader—one who will govern the shifting dynamics of werewolf packs across the country.It is also the year Lethia Ashcroft faces the ultimate humiliation when her mate, her husband, rejects her because of the infidelity she never committed.It cost her the inheritance she and her late father had worked so hard for.When she tries to flee exile while pregnant, she is caught in an accident—one that leaves her possessed by a seductive spirit fox.The creature needs a vessel to ignite her beads and, in exchange, grants Lethia the power to protect her unborn child.But that untamed spirit entangles her with three dangerously irresistible Lycans from Lykon Haven—men who have severed themselves from the fated mate bond.A stoic, protective doctor.A brooding, dominant businessman.A charming, playful celebrity.All Lethia wants is to reclaim what was rightfully hers and live a peaceful and comfortable life, alone with her baby. And she must get it—no matter what.But the mischievous Moon Goddess seems to take great pleasure in twisting her fate.

In the distant future on Earth, there was a girl with God-like powers. That girl is the last survivor of the former human race that flourished in ancient times.

The Ancients.

And on that very same Earth, a new breed of humans with the ability to wield Magic emerged.

That girl began to observe the new human race silently.

Sometimes called a God, other times called Satan, that girl continued to observe the new human race.

This is the story of the happenings between the lonely girl and the hardworking new human race.