Return of the Calamity-Class Death Knight - Chapter 27

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.

'I'm not an ambitious person,' is something Reiner often says. He just wants to hang around with the Straw Hat crew, traveling the world while collecting the souls of the dead. From Kuro... Arlong, then to 'Old Sand' (Crocodile)... the Golden Lion (Shiki)... As he gathered more and more, the 'style' started getting progressively weirder.A demon with goat horns and a snake tail? Okay, maybe I can understand that. But a 'Chainsaw Demon'? What the heck is that? And where did you even pull this 'Sukuna' from?!When the Summit War kicks off, Sengoku and the Three Admirals stare at Reiner, who is sitting calmly upon the execution platform.'What? You're saying these incredibly strong individuals are undead beings controlled by him?!''How is that possible! Isn't he just some handyman doing chores for the Straw Hat crew?''Seriously, man... You call *this* logistics?!'Hearing this, Reiner gets annoyed: 'If doing literally every kind of job isn't called logistics, then what is!?'------(Story follows the Straw Hats' journey + original plot elements. The main character is neither overly righteous/naive nor does he turn evil/dark.)

“The True Form Of Order is chaos, It is a tale as old as time itself!”Since Dungeons began appearing around the world, things have changed. The world has evolved, letting dungeons alter the genetics of humans, giving some of them abilities and powers that no ordinary person would have.These abilities were called magic, and the ability to use them or even control them was called having mana. Almost 80% of the world’s population has gotten this ability. When a person who awakens their magic is seen, he or she will be taken for evaluation. To see their strength, there were strong and dangerous warriors who had to be used to keep the dungeon at bay and make sure that nothing happened to the world.Amid all this chaos, Darius Winters, a typical loser trying to make sure he would make enough money to pay for his sister's treatment, joins a guild on a raid. When his life is changed, Darius gains a powerful system, and he can get stronger than he was; the system makes him potentially the strongest warrior in the city.But he chooses to hide from the spotlight and take care of his sister. But how long can he keep up with that? when he is thrown in the middle of a brewing war between divine beings

Xu ZiYan has a little brother, and that little brother is gay. As an older brother, he has always felt a bit regretful.

One day he transmigrated into the inside of a novel and found himself with another chance to raise a younger brother.

Immediately rolling his sleeves up to prepare for battle, he planned to raise this little brother into an exceptionally good man! And a perfectly straight one!

Taking a lesson from his past experiences, he continuously perfected his training plans.

Clearly, he strangled any opportunities to turn his little brother bent in the cradle, yet why was it that the little brother he had used all his heart and blood to raise — was still a gay guy!!!

And he was a gay guy who made him his target!!!

Your father ain’t playing around anymore!

A body you can save, however a warped soul……how do you want him to save it?! What a godly problem!!!

Twisted black-belly younger brother X irritated wifey older brother.

- Description from Novelupdates