Magic's Return: I Can See The Spirits - Chapter 191 I have anger management issues.

Reborn into a fantasy world of magic and aura, Rowan is the second son of a ranch family living boringly in a backwater village, with no magic and no inheritance.To avoid rotting away in the countryside, he becomes a mercenary instead. Better to die fighting than waste away.After his first kill, the Black Dream awakens: a power that lets him plunder abilities from everything he defeats.But it's more than that. When he fights alongside others, their techniques become his: a master archer's deadly precision, a hunter's supernatural tracking, an assassin's shadow-step…Every ally becomes his arsenal.Ascension awaits! From the lowly dirt to the throne of the gods.

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.

Introduction to One Piece’s Bounty System: Tianlei crossed the One Piece World and become the nephew of the Navy Admiral ‘Sakazuki, ‘Akainu’, Tian Lei thought it was very outrageous until he found himself having a [bounty system] that can be exchanged for everything in the world of One Piece. As long as you kill or capture pirates, you can draw a Skills, weapons, and devil fruits. Such as ‘Navy Six-style’ ‘Overlord color Haki (Busoshoku Haki)’ ‘sense color Haki (Kenbunshoku Haki) ”armed color Haki’ ‘devil fruit’ ‘sword skills’ have everything!

- Description from Novelupdates

Traveling to a different world, a bizarre, mysterious and vast world unfolds in front of Zhao Ji. He wants to run hard in this vast world and live a free and easy life.

- Description from novelbuddy