The Simple Life of Killing Demons - Chapter 45Book 11:

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.

The world experienced a cataclysmic change, and countless spatial gateways appeared out of thin air.

After the Calamity War, the final and most devastating conflict to decide who would claim the Divine Throne, Kael Medici stood as the last survivor.He had led armies, fought with unmatched ferocity, and performed legendary feats. Yet in the end, his fate was no different from the rest. He perished like all the others, the final casualty of the Great War, his hand just shy of the throne he so desperately desired.But when he thought it was over… his eyes snapped open.He had returned to his youth, his memories intact.The path to divinity is drenched in blood, and the battle for supremacy is merciless. Yet Kael has already endured this once. This time, failure is not an option.With the memories of his past life, dominating talent and and a mysterious power awakening within him... The preparations to reach the Divine Throne were complete.

WSA 2025 ENTRYIn the Grand Land of Baltalaha, the Awakening Ceremony is the most anticipated event of the year, where 15-year-olds from across the kingdoms discover their innate powers. Morvane, an orphan raised by a healer grandmother, eagerly joins the celebration with his best friends, Luna and Esmael, each dreaming of the abilities that will shape their destinies.As rulers from the six kingdoms display their awe-inspiring powers, the arena buzzes with excitement and wonder. One by one, children receive marks signifying their newfound abilities, the crowd erupting in cheers with each display of elemental magic, healing, and unique gifts.However, when it’s Morvane’s turn, silence falls over the arena. No mark appears on his shoulder. Confusion ripples through the crowd, and Morvane’s heart sinks. In a moment meant to define his future, he faces an unimaginable question: What does it mean to have no power in a world where everyone else awakens?Unbeknownst to all, Morvane’s fate is tied to a mystery that could reshape the balance of Baltalaha forever.