King Shura - Chapter 33. Nanman Beast Gate

In a world where dungeons loom like dark secrets and monsters stalk the land, Rem’s awakening shattered the status quo. A surge of raw power flooded his veins as the Monster Monarch System bound itself to him, unlocking a terrifying potential.Each heartbeat echoed with the promise of countless souls waiting to be absorbed—skills, abilities, and monstrous strength ready to be claimed.Fuelled by an insatiable thirst for power, Rem set out on a deadly quest, driven by one singular goal: to rise above the chaos and stand at the pinnacle of the world. With nothing but the deadly abilities granted by the System, and a burning will to crush any who dared stand in his way, he carved his path through savage lands and ruthless mages.The hunt for strength never ends. The battle for supremacy has only just begun. Rem’s eyes are set on the throne of the Monarchs, and the Monster Monarch System will ensure nothing stands between him and his destiny.The grind was eternal...

A boy from 21st century Earth, met an accident and later was reborn in Naruto’s Ninja World.
He is born in Uchiha Family and becomes the useless brother of Itachi Uchiha and Sasuke Uchiha…. Let’s see how he changed the Naruto world.

- Description from Novelupdates

Mark hatched out of an egg one day, reincarnated as a demon!His body was as strong as iron, instincts capable of noticing a silent fly multiple meters away. Eyesight sharp enough to see the small holes in an enemy’s clothing.Moreover, he also had a system.[Soul Devourer][Eat souls to grow stronger.][Mind-type Demonic Tricks have been derived out of your demonic bloodline!][Heart Input!][Input unsolicited thoughts in an enemy's heart and influence them!]Mark took a deep breath.How can he allow himself to live a mediocre life after being given this second chance?Now, he wanted it all!Women, wealth, power, status, and even eternal life!His ambition was set, his heart was on fire. A demon had been born.

Have you ever thought about how your life would turn out at the age of 18?Well before I could even say that I was an adult to even say I was going to conquer it.The world had seemed to already be determined of what mine and the rest of humanity would be when the first Leviathans was made public to our world.