In Naruto: Reborn With Talent - Chapter 423 Ch. Hard truth

Being taken away of all his freedom, Noah was thrown into the jail accused of a murder he hadn't committed.

This incident broke his personality permanently, getting out of the jail Noah started living as a shut-in giving up at everything.

Noah read novels as a mean to pass his time, while reading novels an particular novel caught his eyes, it's name was 'the hero of velveric fights the demon lord'

'It's a harem novel......'

That was what Noah had thought in the beginning but, it all changed at the end of the novel.

'What the Hell's with this crazy novel!'

The protagonist and all his harem members were killed and in the end the demon Lord took over the world.

It was then, after finishing reading the novel, Noah started coughing out blood and succumbed to his lung disease.

Opening his eyes Noah found himself in a body of a 8 year old kid of the Melvix family which appeared in that crazy novel.

He was known as the garbage of the Melvix family by all the knights and family members but that didn't matter to Noah. What matter is that-

'It's impossible to survive in the novel if you are not strong enough......'

A hero must be compassionate, selfless and courageous.But that isn't all. Because a hero must also be powerful.In this world, power is everything. Strength decides who gets to save lives and who's left with community service. That’s why I was nothing — a rank 50 E-Class reject, skating through the streets, saving what little I could while the real heroes battled gods and monsters.Then one day, I died. Almost.Dragged into the abyss, I was given a second chance: the Forever Core. An armor that evolves. A system that never stops adapting. Every battle, every hit, every mistake, I come back stronger.Now, the monsters that once crushed me can’t kill me the same way twice.I must adapt. Evolve. I must grow stronger and fight harder. Because humanity is worth fighting for.Even if I have to burn every villain alive to prove it.

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.

Imagine being forced to live, after death, as incorporeal bodies trapped in a vast space of nothingness for thousands of years, with nothing to do but exchanging past memories with other cohabitants (read: weirdos). Everybody wanted out, but there was no way to leave the Void…

Until one day, a young man was finally summoned, as a powerful but reluctant mentor, by a bubbly and motivated but completely naive young girl. Baiyi, finally out of the Void, was the only one who could save all of the other 32 souls from their prison and his summoner might just be The Key to their freedom.

However, Baiyi had to use the techniques and abilities the other souls had taught him throughout the years, and together with his own extensive knowledge of anime and game tropes from his shady and dangerous past as an otaku, to face the biggest challenge of them all: training the clumsy young girl he was forced to partner up with… into a competent sorcerer!

This is a story of heroic adventures, cunning strategies and romantic tales. How will our MC thrive in a world completely strange to him? Where will his ambitions and abilities take him in the palace?

- Description from Novelupdates