MTL - Rich Devil - Chapter 507 , with billions of people

A young man, a modern-day history and war enthusiast, finds himself reincarnated in the body of an orphan — one destined to inherit a small, struggling barony from his dying uncle. But fate offers no easy path. Inside the family, greedy rivals lurk, eager to steal his inheritance. Outside, hostile neighbors eye his weakened lands, ready to tear it apart at the first sign of weakness.This is a tale of ruthless ambition, cunning strategy, and relentless struggle. From a powerless orphan to a baron, from the weakest barony to the mightiest duchy — he will rise through blood, steel, and fire.

Despite being the ruler of a nation, nobody was willing to marry the vicious man with a bloodlust.

Crown Reylin loved three things; flames, fireworks, and bombs. He didn't spare any of these against those who insulted him due to his family. No, Crown Reylin wasn't born in a poor family. He was born into an outstanding family with every descendant prevailing in their industry! But as the first immersive game appeared on the market, Crown Reylin stepped in... to enjoy more of his hobby!

Flames, fireworks, and bombs! Empresses, the kings and their princesses, and many more people will feel them!

It was Reylin's time!

[Pre-Author's Note: MC develops as time passes, it starts out slow but surely]“The Apocalypse isn't just fit for anyone... Without Strength, you're just a tool waiting to be exploited, So hurry the fuck up and get some strength already,”The world ended in an instant.One moment, Simon, a 20-year-old game designer, was sitting at his desk, immersed in code.The next, the sky cracked open and monsters poured into the streets.Werewolves with claws sharp enough to slice through steel.Undead skeletons that marched with deadly purpose and Zombies that infected humans with the power of their bite.The gods had unleashed an apocalypse, and humanity was no longer at the top of the food chain.Simon ran, he survived... and then he was granted a power.|Congratulations You have been binded to the Vampire Overlord System|He was something else.A vampire overlord.Yet the Apocalpyse had only just begun...