The Main Characters That Only I Know - Chapter 77:

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.

In the mysterious MMORPG 【ExoGenesis】, the extraordinary age of transcendence has arrived on Terra. Tristan is reborn on the very day the game launches, awakening an SSS-level talent: the Sniper God.[Sniper God (SSS-Level)]- Effect 1: All ranged attacks are guaranteed to hit, and the damage type is changed to true damage.- Effect 2: For every meter of distance from the target, damage increases by 10%.With such an overpowered talent, Tristan’s choice is clear—he becomes an assassin!With deadly precision and the ability to strike from miles away, Tristan proves that an assassin doesn’t have to fight up close.

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.

What if one could defy death and, instead of perishing, be reborn?

Such a situation happened to Kieran Silver after succumbing to his circumstances caused by wicked superiors.

After being reborn, Kieran's desires changed and he considered the many routes.

The route that resonated with him most was Zenith Online, the MMORPG that changed his life initially.

In his past life, he was a bare minimum kind of guy, using the least at its maximum potential. However, his current outlook changed.

Accomplishing the bare minimum? No, he would go above and beyond!

On his path to greatness, creating an immortal legacy that resounds throughout the universe, dethroning his former guild, and other grand feats will become his stepping stones.

To ensure his aspirations become reality, Kieran must walk a path where he becomes an entity prime for destruction.

Magic, destruction, and ancient practices are just a few of the factors that mold his ultimate power. What began as one of the Hidden Classes would ultimately evolve into a one-of-a-kind entity!

The ultimate power isn't given or born, it is manifested.