The Underworld Judge - Chapter 44 - Ghost Behind the Door

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.

They hunted my kind for extinction but I came back as their nightmaresnon human mcDarian once the strongest Dragon Knight in the Empire, died protecting the last dragon from extinction. Betrayed by his comrades and burned alive by holy fire, he vowed vengeance with his last breath.But the gods answered—with a curse and a gift.Darian reincarnates hundreds of years later... as the last dragon egg hidden in a cave deep beneath the earth.Now, inside a fragile shell, he remembers everything. The betrayal. The genocide. The lies told by the human kingdoms. And as his body slowly grows, so does the power of ancient draconic magic—and the System embedded into his very soul.> [Draconic Evolution System Activated]Choose Your ElementUnlock Ancient MemoriesDevour Magic Sources to Accelerate GrowthHatch When Power is ReadyHe must hide from dragon hunters, manipulate desperate adventurers, and absorb mana from the dying world to hatch once more—stronger, darker, and more terrifying than ever.And when he emerges?> The world that burned him will feel true fire.

Traversing into the world of “My Hero Academia”, the awakened personality is actually a stand-in [World].

In the face of the invitation from All Might, Wu An said: “I have no interest in heroes, I just pursue power, and I have nothing to do with women.”

Facing the provocation from ALL.FOR.ONE, Wu An opened his arms and summoned his stand-in.

“THE. WORLD! Time! Stop!”…

- Description from novelbuddy

The universe is big, and Hayden’s about to invade it. Being drafted into a demon army wasn’t on Hayden’s bucket list. But when his soul is shoved into a human soldier on the eve of a new invasion, it’s not exactly like he can appeal the decision. Surrounding Hayden are demons, excited and ready. For them, the invasion promises a feast of souls and new growth. Their target? Berlis — a sword and sorcery realm straight out of classic fantasy. Hayden’s human status puts him at the bottom of the totem pole, meant to be cannon fodder that soaks up damage and dies first. But as he plunges into the carnage, he’s learning that he was born for the madness. Readers can expect: + Grimdark action and violence + Fighting, lots of it + Multiple worlds and magic systems + Slow burn