Reincarnated as a demon inside a dungeon - Chapter 117

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.

He shattered the heavens… and got isekai’d into a crazy desert survival game!Xu Tao cultivated for ten thousand years, defying death and destiny to reach the Divine Heaven Immortal Stage.But just as he touched the heavens—The heavens kicked him into a world based on a full-dive VR game.Now he’s got no Qi. No weapons, no cultivation… and no pants.Just a desert full of monsters, a glitchy “Lost System” that won’t shut up, and knowledge forged from millennia of clawing his way to the top.Enemies? Weaklings.Mystic beasts? Drop garbage loot.Level caps? He’s Xu Tao.He didn’t spend ten millennia chasing immortality just to get wiped by a scorpion in a tutorial-zone!But he’s definitely not here to play. He’s here to ascend—again.Even if this time, he has to grind EXP and punch sand beetles to do it.But wait... That's not all...? He could also... What?!

A skilled thief gets a system in an Alternate Wizarding World. The system seems useless in the beginning since he hasn’t unlocked any features. But…

[The very first feature of the System has been unlocked.]

[Congratulations. You’ve unlocked the class feature. Due to your existing skills and experience, you have gained the Special Class "Arcane Thief" as your starting class. There’s nothing an Arcane Thief can’t steal. The more you steal, the more your Class will progress.]

[The fields of expertise include:

— Stealth Magic
— Wards
— Traps
— Enchantment
— Pickpocketing
— Knife/Short-Sword Wielding]

Wait…this is just the first feature?

Roan transmigrated as an FBI investigator.Several years later, a journalist interviewed the world-renowned detective Roan Greenwood and asked,“What made you persist in solving cases for so many years?”Roan tilted his head and glanced at the sports car beside him, the villa behind him, and the beautiful woman inside the villa. He smiled slightly and said,“Well, the bonus after solving the case.”“What?”