Aoyama Yuito Daichi was just a normal teenager-an otaku with big dreams and zero athletic ability-until the day he was hit by a truck (yes, the cliché). When he woke up, he wasn't in his world anymore. He was in My Hero Academia-the land of quirks, heroes, and endless possibilities. Convinced he was destined to become overpowered, Aoyama dove headfirst into this new life, ready to make a name for himself. But there was one small problem: he had no quirk. None. Zilch. While everyone else was flying, blasting, or smashing their way through life, Aoyama had nothing but his wits and anime knowledge to survive. Just as he was starting to think the universe had handed him the worst deal, Aoyama discovered something incredible-he wasn't stuck in MHA. He could travel to other worlds. From fighting demons to exploring universes he once thought were just fiction, Aoyama's journey is about more than gaining power. It's about finding his purpose in a multiverse that keeps throwing challenges his way. No quirks? No problem. Aoyama's going to rewrite the rules of being a hero, one world at a time. 1st world(main)- My Hero Academia 2nd- Demon Slayer 3rd-?

Y/n L/n, once the hunter of Yharnam, is drawn far from those blood-soaked streets to Japan. Here, he confronts a new breed of beasts... Demons.

In the Heian era, the first of his kind appeared. Kibutsuji Muzan. A young man, cursed with a disease that promised to claim his life before the age of twenty. Desperate treatments prolonged his existence, but in delaying death, they birthed something worse. He gained strength beyond human measure, yet the sun itself rejected him. Its touch seared his flesh, its light threatened his very life. That... Was the beginning... The birth of demons. But even before that... There was Shinobi. That's right. There was Shinobi.

Shinobu Kocho x Male Reader "But I have to move on. I have to continue. So I can see them again and make everything right."

Isamu Takahashi. A member of the Demon Slayer Corps. Alongside him is a childhood friend, Tanjiro Kamado. Together, they embark on missions to annihilate demons that murder the innocent. But Isamu has a secret that not even Tanjiro knows. His breathing technique. One that cannot be learned, only passed on through blood. Darkness breathing. What will Isamu accomplish with this breathing technique, What will the Hashira think of it? Will it be enough to stop Muzan?

Yukimura Kaidō lived as a ghost in his life-bullied for his feminine features, beaten until he lost an eye, and too afraid to fight back. He spent his days hiding behind a computer screen, finding courage only in the final seconds before a truck ended everything. Death should have been the end... Instead, he woke up in the Demon Slayer world. [Ding! Compatible transmission target detected. System binding initiated... Binding successful!] [Ding! Congratulations! Host has received: Body Enhancement Serum x1, Total Concentration Breathing: Constant, Dragon Breathing First Four Forms, and 100,000 Yen.]

"A Hashira sent to judge a demon that refuses to kill... and the boy who would give his life to save her. Arata Hoshi, the Star Hashira, is known for his cold precision and unyielding sense of duty. But when he's sent to observe Tanjiro Kamado and his demon sister Nezuko, he finds something he didn't expect: a boy with a heart so pure it could shine even in the darkest night, and a demon girl who greets him with innocent trust rather than bloodlust. Bound by orders, Arata must decide-will he follow his duty, or will these siblings change the way he sees the world?" All Rights to the Creator of Kimetsu No Yaiba

A Maiden is an unmarried woman who says she'll do fine without the need for a man. As the Maiden Hashira, who is a man, (M/n) will fight for a woman's pride. I don't own Demon Slayer or any of the characters besides (M/n).

When I awoke, I found myself in the perilous world of Demon Slayer. Bound to a mysterious system-the Ultimate Defense System! Mitsuri Kanroji murmured in awe, "His strength surpasses even mine..." Kagaya Ubuyashiki nodded in admiration, "Truly, the Demon Slayer Corps' strongest shield." Even the fearsome Kokushibo conceded, "You embody the strongest defense our generations have ever seen." Akaza acknowledged me as an equal, "To master defense to such a degree... you have become a warrior worthy of fear." And the Demon King Muzan Kibutsuji-once unshaken-finally lost his composure, "No... no living being should possess such durability!" In a world where offense reigns supreme, I chose the path of resilience. I do not wield a blade to kill. I stand to protect. No demon shall pass me. No comrade shall fall behind me. I am not the hero this world expected- I am its unbreakable shield.