I have an Apocalypse City - Chapter 541 - : Wild Honey

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.

Why do Gods of Transmigration love to murder their benefactors instead of asking for their help a normal way?That's how Karl got started as well. Murdered by a goddamn goddess, dumped into another world, and told to save her from her problems. You'd think gods would have their shit together, being gods and all. But apparently they do not.Karl, a teenager, who felt the inequality in his already struggling life more than ever before, finds himself transmigrated as a vice principal of a magical academy. The council accuses him of his incapability and his inexperience, believing he's not fit to lead them to the top.[ Mana meter unlocked: capacity F ]Even his cheat skill seems like a useless gimmick as Karl faces the worst students of the academy and the most difficult professors.That goddess better sends his paycheck to his parents in his old world because Karl isn't going to work for free, and if he does this job, the least she could do is pay off their debts.But then again...“I won't accept this fate handed out to me. This world might offer me the fantasies but they can't give me the warmth of my loved ones.”Would he be able to meet the Goddess and return back to his world or would he gets buried under the history of the lands that had once housed Gods and Demons alike?

When the storm struck, they chose Kogan as a sacrifice to save their city... but he found himself in an unknown world, surrounded by strangers who knew nothing of their fate. In a land teeming with enigmatic entities and lurking dangers, Kogan will soon realize that his survival was no miracle, but the beginning of a harrowing trial. Will he find a way to escape, or is this place the grave that was destined for him all along?