My Hero Academia Crossover Fanfiction

✅ SYNOPSIS Billy Howell grew up in the modern city of Silver Heights, known by everyone as the unlucky boy who never got anything right. What people didn’t know was that a strange and ancient force had been sealed inside him since birth. That seal kept his energy weak, his senses dull, and his future dim. One day, a mysterious accident awakens the Eternal Origin Core, an ancient treasure buried deep within him. Along with the awakening comes a strange voice— the Origin System, a powerful system containing rewards, tasks, and an exchange store. From that moment, Billy’s life changes forever. He begins to meet people with hidden supernatural abilities, discovers dangerous underground societies, and learns that the world is far from ordinary. But the biggest twist comes when a strange pull drags him into another world entirely—a place where cultivation, magical bloodlines, and ancient clans rule everything. There, Billy realizes a shocking truth: He has lived once in that world before. And now, all the knowledge, instincts, and battle skills from his forgotten past life begin to awaken. With the system guiding him, Billy rises faster than anyone else. Those who once mocked him are forced to watch as he becomes a name that shakes both worlds.

Two painful memories, fragments of personality and habitual bad luck are all that Hero 67665 has left when he enters the new world. He was promised a happy life and a chance to correct his mistakes, but no one said they would help with this. An ideal world filled with losers, scum, and it’s almost impossible to level up. Let's start with the first unit of experience?

"If he cannot survive in this Realm and ascend to the Higher Realms, then he is not worthy of being my son!” *** Xiao Tian, the child abandoned by his own parents. He once lived a happy life as the crown prince of the Wang Kingdom. But a great tragedy struck his family—his beloved uncle staged a coup, killing his mother, father, and all those loyal to them. However, the death of his parents was a lie. It was merely a scheme—to leave him behind in the Tianwu Realm, the lowest realm in the Universe. Alone, he rose. Step by step, he walked a path filled with hardship. When he discovered that his parents were still alive, anger filled his heart. But it was not blind rage—it became the fire that forged his resolve to become stronger. With unwavering spirit, he climbed from the lowest realm, ascending through each realm—until he surpassed even his father and became the ruler of the entire Universe! “I, Xiao Tian, swear to overturn this injustice. I will reach immortality and create true peace—so that no one will ever be oppressed again across the Universe. Strength shall no longer be the only measure of justice. And if strength is the key—then I shall become the strongest and be the one who defines justice for all of existence!”

Saving a crumbling empire from the brink of bankruptcy should have cemented Samuel Hayes as a hero, but instead, it only invited betrayal. To the world, he was just a washed-up nobody, a man too weak to fight back. But when he stepped into the city’s most dangerous den, the facade cracked. Piece by piece, Samuel Hayes unveiled the truth—a force untouchable, unrelenting, and utterly unstoppable.

In the darkest corners of Marseille, where hope sinks faster than a rusted anchor, an overdose should have been the end for Jean Valéry. But for this broken Navy veteran, death was only a doorway. He awoke with another soul burning within him—that of the Black Sea Alchemist, the failed guardian of Atlantis, whispering of ancient magic and the vengeance of the deep. Every corner of the Old Port is now his laboratory, every drop of polluted saltwater an ingredient for deadly potions and poisons. Fractured memories guide him, while a raw and dangerous alchemical power demands release. But Marseille is not only a haven for crime bosses. Deep within its murky waters, an ancient power has awakened, demanding accountability for the failures of his past reincarnations. To save the city, he must first seize it from the grip of the underworld. To atone for the sins of the past, he must become a monster in the present. This is not a story about the rise of a hero. This is a story of transmutation—how a broken man is melted down in the crucible of magic, malice, and destiny. The question isn't whether he will survive, but what he will become afterward: an unbeatable crime king, or a protector damned by the sea?

Thaddeus Crane spent three years in prison for a crime his wife committed. Upon release, she divorces him instantly—unaware he’s inherited a global empire. Now his blind sister has vanished into the city’s darkest corner, sold as collateral for a business deal. Armed with unlimited power and three years of ruthless training, Thaddeus will burn down anyone standing between him and his only family.

Fang Yun, a boy who was once branded by one of the sects as someone who would never be able to possess martial arts abilities, suddenly received a miraculous blessing of immense power when he was hiding among the ruins of an ancient temple. However, behind this blessing lay a great mission he had to face. A man known as the Dark King, who had formed an alliance with the Demon King, was plotting to conquer the earth and turn it into the center of rebellion against the Celestial Beings. Fang Yun’s master then entrusted him with a mission to search for four sacred relics that would later be forged into a single sword of unimaginable power. With this sword, Fang Yun would one day face the Dark King and the Demon King.

In the quiet city of Whitelock , New Zealand, secrets lurked beneath streetlights and silence. The government had one strict rule no mutants. Anyone caught with powers was executed on sight. No questions. No trials. Just blood and law. Behind the polished smile of Mayor Clark, fear ruled. His only son, Alan Clark, lived a life wrapped in privilege fancy cars, spotless uniforms, admiration from nearly every girl at school. Yet beneath all that, he felt... incomplete. Like something in him waited to awaken. It all started the night of the President's son's party. The lawns of the Danny estate glittered with golden lights. Music thundered. Laughter spilled into the air. Teens danced like they had no past no future. Just now. Alan stood alone at the edge of the pool, a red solo cup in hand, untouched. His jaw clenched each time Danny passed by with his arrogant smirk. Memories from the Freshers' Night burned in his mind shame, humiliation, rage. He should've never come here. Then it happened.

Kai Wang died a loser–beaten to death in an underground fight while he watched his girlfriend kiss his killer. Kai gets a second chance at life–but it comes with a price written in blood. Granted by a mysterious system run by seven faceless beings. Now reborn with power he must fight his way back to the top while completing missions for his faceless masters. He must save his dying mother, destroy those who betray him, and become the unstoppable figure no one expected. But every mission pulls him deeper into darkness and one question remains–will he save his soul or lose it chasing power?

Kai Gibson has always been ordinary—too ordinary for a city like Harborview, where power, influence, and fear rule every street corner. After losing his father under mysterious circumstances and struggling under crushing debt, Kai is pushed to the edge of survival. But everything changes the night he’s ambushed behind an abandoned mall and a strange surge of energy awakens inside him. With the rare ability known as Tactical Insight, Kai begins to see the world differently—patterns, threats, weaknesses, pathways to victory even when the odds are against him. Suddenly, the once-weak young man becomes a rising force in Harborview’s underworld. But Kai’s evolution comes with a price. Every step forward drags him deeper into a web of enemies: street gangs, corrupt elites, hidden organizations, and people he once trusted. Betrayals strike from unexpected places, and Kai learns that the attack that awakened his power wasn’t random at all—it was planned. Now trapped between shadowy forces that want to control him and others who want him dead, Kai must level up faster than his enemies expect. Each chapter pushes him through higher stakes: • deadly ambushes • shocking betrayals • growing supernatural abilities • strategic face-slapping comebacks • climbing from the lowest rung of society to a position of unstoppable strength As Kai climbs, he uncovers the truth behind his father’s death, the origins of his new power, and a hidden war brewing beneath the city’s neon lights. To survive, he must rise. To win, he must become more than human. And to uncover the truth, he must be willing to face the darkness inside—and the monsters hiding in plain sight. Harborview will remember the name Kai Gibson… whether it wants to or not.