One Piece: My Crew is from Other World - Chapter 364: Blackbeard Reappears, Mysteriously Attacks!

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.

Chu Qiao was known as Agent 005 within the Secret Service’s 11th Division in her former life. She was locked up in the Secret Service’s prison as she was framed. After she successfully broke out from prison, she sacrificed her life bravely to preserve the Secret Service by defusing a bomb meant to wipe them out.

Majiatisi Lei En, the sole Descendant of the Heroes is the nightmare of his entire town.

The apprentice of a proud Warlock, Lei En works hard to learn his trade unknowingly causing mayhem for those around him.

So when he stood on the tower of the Supreme Wizard, shouting with a heroic flair:

”I want to be the greatest of the alchemist of the Shenji Continent!”

A resounding roar of, “Boos” from the townspeople was the only response he got.

- Description from Novelupdates