I have an Apocalypse City - Chapter 453 - : Dissection

The moment when mercenary leader Kwang Hwi receives video game like abilities, the world is suddenly thrown into chaos. A thick fog envelops the Earth, bringing with it savage, otherworldly monsters. At the same time humanity has been rendered defenseless against this onslaught, as the strange fog turns most weapons to rust. With mankind spiraling towards oblivion, it is up to Kwang Hwi, with his new abilities, to save the world. Watch as Kwang Hwi leads his militia and becomes the last bastion of humanity. Will he be this world’s savior, or its conqueror?

Elliot Hawthorne, had transmigrated into the body of a struggling apprentice mage, and now had one simple goal, summon a small, harmless spirit to pass his magic academy’s final exam. But thanks to a mistranslation in an ancient grimoire, he instead summons Azrael, the almighty Demon King.That would’ve been bad enough…. but then the spell accidentally binds them in an unbreakable marriage contract.Now, Elliot is stuck with a possessive, dangerously powerful, and ridiculously affectionate demon husband who:Carries him everywhere because “His cute little summoner’s feet shouldn’t touch the ground.”Summons hellfire just to keep Elliot warm when he complains about the cold.Declares war on any kingdom that dares to call Elliot “single.”Refuses to be unsummoned.“Why would I leave? My husband is here.”Worse, every holy knight, exorcist, and jealous god now wants Elliot dead for “stealing” the most powerful demon in existence.. Stuck with a one-in-a-million system dungeon and a devilish Demon husband, Elliott's life is constantly on the brink of disaster...But when Elliot starts uncovering secrets about the contract, he realizes…Did I really summon him by accident? Or… was Azrael waiting for me all along?One way or another, Elliott’s unlucky life becomes worse. An impending doom threatens the existence of the human and mortal worlds.And as if that wasn’t enough, he’s also stuck with a Demon for a husband.But maybe, just maybe… being bound to a dangerously powerful Demon King isn’t the worst fate after all.

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.

Darius had nothing going for him. Ever since he could remember, he had been treated as absolute trash by his boss, who was one of the greatest scouts for actors, singers, idols, and anything you could think of.However, everything changed one day when a truck rammed into him and sent him back in time to start his career as a nobody. But, this time, he hadn’t returned empty-handed. He received a great talent that would make him the best Manager the world had ever seen.【Talent Booster: You can increase the talent of those close to you. The closer and more intimate they are, the better the skill's effects will be.】You can’t sing? Sleep with me, and you’ll win a Grammy.You can’t act? Sleep with me, and you’ll win an OscarYou’re talentless? Sleep with me, and I’ll make you whatever you desire.