How To Hide The Tyrant's Child In The Apocalypse - Chapter 49. Welcome to the world, little Bella

Let her shout out: “Oh handsome and sweet-talking Tokyo gentleman, I must have you. You are mine!”This is the story of how a boy from Iwate Prefecture became a Tokyo gentleman.

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.

When low-level healer Elias Vale stumbles upon a cursed cocoon in a forgotten ruin, the last thing he expects is to hatch the reborn soul of the Demon Queen Revantra—in the form of a scared little girl.To save her from divine execution, she binds herself to him through an ancient soul pact, fusing their fates. Now, Elias is stuck raising the former destroyer of worlds—who can barely tie her shoes, but occasionally melts furniture when she pouts.What starts as reluctant guardianship soon spirals into something far more dangerous. As Rhea (her new alias) grows stronger, older, and far too attached, Elias must keep her identity hidden from zealous church inquisitors, ambitious heroes, and the remnants of her own loyal followers—some of whom want her dead... again.But the longer he protects her, the deeper the bond grows—and the harder it becomes to tell who’s really taming who.Because the world once burned beneath her wings……and this time, she’s not letting him go.

[You have been chosen as a Lord of the Intergalactic Lord Project.] [Your reward: A floating island to call your own.] [Your mission: Build your kingdom, summon legendary allies, and dominate the worlds!] [Your advantage: An SSS-grade Ultimate Gacha System.] Atlas Blackthorn, the newly chosen Lord of a floating island, wields the power to summon legendary warriors, powerful artifacts, and, of course, waifus. With boundless ambition and the Ultimate Gacha System at his side, Atlas sets out to become the strongest Lord in all worlds. How far will his ambition take him?