Disclaimer: I do not own My Hero Academia/Boku No Hero Academia, or any other property in this work that I did not make myself.

Hizashi Yamada vs. the demon horde

Chapter two: Things turned on their heads

Hizashi, while standing protectively in front of his good friend Muzan Kibutsuji, stood against the evil demons Rengoku and Shinobu, who were once noble Demon Slayers centuries ago but now had been resurrect by their patron lady in a bid to capture Muzan. "I don't know who you guys are," Hizashi said, "But there's no way I'll let either of you harm even one hair on Muzan's head, you evil demon pricks!"

Rengoku smirked in amusement. "...I can tell that the humans of this time period sure are strong. I wonder how it would go if-"

"ACK!" Shinobu cried out suddenly in surprise, cutting off Rengoku as the both of them were suddenly trapped in blobs of cement that quickly dried out, trapping them and leaving only their heads sticking out of the blobs. The heroes turned to look at Cementoss, who was just now getting up from a kneeling position.

"Will this hold them?" Cementoss asked after turning to face Muzan.

The progenitor of demons nodded in the affirmative. "Should hold them long enough for Hizashi to go get his Nichirin Sword that he tells me he has."

Hizashi nodded in confirmation. "Bought it off of a lady who needed money to buy medicine for her daughter." Hizashi then ran out of the room, then came back in a few minutes later, carrying a katana in a black scabbard. It had a black hilt, but the hand guard was an orange flame shape with a red border. Hizashi drew the sword, revealing a pitch black blade.

Rengoku's eyes widened upon seeing the Nichirin Sword that Hizashi owned. "...That's Tanjiro's sword. I can tell since his was solid black but I was told he switched in the cross guard from my old sword." The demon, memories of his human past seeping through, snarled angrily at Hizashi for reasons that honestly escaped the once Demon Slayer. "...What are you doing with his sword?"

"I thought it'd be cool to own a Nichirin Sword," Hizashi replied with a shrug, "Now you and your little butt-fuck buddy here will tell us everything, or else I'll cut your heads off."

Shinobu opened her mouth wide as she hissed at Hizashi, and a much smaller version of her head came out on a very long smaller neck, with the smaller Shinobu head also hissing. The smaller Shinobu head was pulled back in before regular Shinobu talked. "How dare you speak of his sword as if it were a one-hundred yen trinket you bought from somewhere! You will pay dearly for such an offence, human!"

"Look, just tell us why that patron lady bitch of yours wants to kidnap Hizashi's friend here," Hound Dog said, "Maybe we can reach a compromise somehow maybe."

The two demons settled down. "...Although our patron lady has taken many of the powers and abilities that Muzan once held," Shinobu began, "That doesn't change how Muzan is the progenitor of all demons. Because he is the first, it makes his demon blood special."

Muzan scowled bitterly. "...I can't turn others into demons anymore. Why is my blood special?"

"Because it was mixing some of your blood with hers," Rengoku began to explain, "And injecting that mix into certain persons, that our patron lady was able to resurrect two certain persons as demons. Using just her blood on its own didn't work for some odd reason."

"There's still one person left that our patron lady wants to resurrect," Shinobu went on, "Who won't return by just her blood on its own. Our patron lady wants us to kidnap you and bring you to her so that she may take some of your blood and mix it with some of hers in order to inject that mix into the person she wishes to resurrect."

Shrugging while he and the other UA staff members in the room all wore uncomfortable looks on their faces, Hound Dog said, "O... okay. Does... does she need all of it?"

Gently shaking her head, Shinobu replied, "No, just a pint. But our patron lady plans to kill Muzan after resurrecting the third certain person anyway."

"What... what does your patron lady want to do after she resurrects this third certain person?" Sekijiro asked as he looked at the bound demons.

Because only their heads and necks weren't trapped by cement, Shinobu and Rengoku couldn't actually shrug. However, Rengoku did lean his head to the side somewhat in a manner that gave the vibe of a shrug. "No clue. All she mentioned in that regard is that once she has all three certain persons resurrected, she intends to go off on a search for something with them, leaving the other demons and I to our own devices."

"She said we're free to do as we wished so long as it won't interfere with what she wants or otherwise impede her in any way," Shinobu went on. Giggling like a loon, Shinobu added, "I'm going to kill so many humans! Except for the fat guys, I plan to rape those instead!"

"Fat Gum's virginity is at stake!" Hizashi screamed as he swung his Nichirin Sword at Shinobu's neck, slicing clean on through and cutting her head off, sending it to the floor where it rolled until it came to a stop so that Shinobu faced them. Shinobu's expression was pure angry fury as she hissed at Muzan and the humans, with her tongue coming out again as a smaller, thin long neck with a mini Shinobu head on the end that also hissed at her enemies. Shinobu's head then burst into ash, as did Shinobu's body still trapped in the cement.

After seeing what happened to Shinobu, the humans aside from Hizashi all turned to look right at Hizashi and Muzan. "Will..." Aizawa began, somewhat at a loss for words, "...Will that happen every time a demon's killed?"

Shrugging, Hizashi replied, "Dunno. But I do know a demon can only be killed if beheaded with a Nichirin Sword." Holding up his own Nichirin Sword, Hizashi went on, "And I got the only one that we have access to."

Throwing his hands up into the air, Cementoss said, "Well that's just grand! The demons can only be killed one way with one specific weapon, and we only have one of that weapon!"

"Actually, I don't think we have to worry too much, blocky human," Muzan said. Turning to look where Rengoku was still pinned, Muzan said, "When I still had the ability to sire demons, those I sired were able to easily break out of holdings such as that. If this one here and his partner who my good chum Hizashi had just killed were of the same quality of demons as what I could of made, then the two of them would of long since broken out."

"Well my patron lady had only just taken your powers," Rengoku explained, "She needs time to focus on them to make them catch up to the point you had them at before she took them from you."

Muzan nodded in agreement to the point. Turning to look at the humans, Muzan went on, "I believe that the blocky human may be invaluable in stopping the demon girl who had taken everything from me, as he can just trap all of them so that Hizashi can easily behead all of them."

Pointing to Cementoss, Hizashi said, "Wait a minute here, Muzan dude. Are you trying to tell me that Cementoss of all people is going to play a vital main role?"

"Well fuck you too, Hizashi," Cementoss said dryly.

Turning to look at the human pro heroes, Muzan said, "We have a shot at stopping the demon girl who took all of my powers! With Hizashi's Nichirin Sword and the blocky human's cement powers, we could very well save the day!'

"There's just one thing left to ask," Aizawa said. Turning to look at the trapped Rengoku, Aizawa said, "Who exactly is your patron lady?"

Rengoku laughed at the humans before him. "Oh please!" Rengoku sneered, "Like I'd ever betray her! Lady Nezuko Kamado would have me killed if I told you humans who she-" Rengoku stopped short in what he was saying, a dawning look of realization on his face. "...Aww shit." Suddenly, Shinobu's head re-materialized from ash, hissed at Rengoku, then flew up and proceeded to eat his face until she had killed him, before dematerializing back into ash.

After Rengoku's remains collapsed into ash, the heroes all turned to look at Muzan. "...Please tell us you know who this Nezuko Kamado person is, Muzan," Sekijiro said.

"I do," Muzan said, "Nezuko Kamado, in the age of demons and Demon Slayers, was an ordinary girl I turned into a demon for shits and giggles. In the end, she ended up proving vital to my defeat which saw to my temporary death, resurrecting on my own roughly a few months before I had met the first human who I could truly and honestly call my friend."

Holding up a hand, Hizashi said, "Yo. I first met Muzan shortly after All Might first started doing only a few hours of hero work a day."

Toshinori, who had long since come back into the room, said, "You met Muzan shortly after my first battle against All For One?"

Turning to look at Toshinori, Muzan said, "You know that All For One guy? The very fellow who was trying to step on my toes by declaring he'd be the next lord of demons?"

"I'm not surprised that All For One said he'd aim for something like that," Toshinori replied dryly.

Shaking his head, Muzan said, "The last I heard about him was sometime about a month prior to that chaos in Kamino that Hizashi told me about. At that point, all I knew about him was that his true ultimate goal was to gather the forces needed to destroy the secret vampire convent working in the background of the Japanese underground."

"Secret vampire convent?" Aizawa said, sounding and looking alarmed.

"I think we're getting off subject here," Hizashi remarked. Looking to Muzan, Hizashi asked, "Can you tell us where we can find Nezuko? Because if we defeat her, then we ought to be able to foil her plans and save the day."

Muzan nodded his head once in the affirmative. "I do know where to find her, yes. I also know where to find someone who can help us by supplying us with some doses of a drug that can turn a demon back into a human." Giving the humans a wry look, Muzan said, "We could potentially turn some of the demons that Nezuko resurrected from the dead back onto humans and get them on our side."

Aizawa held up a hand, getting all eyes on him. "Question," Aizawa began, "The fact that you know where to find Nezuko suggests that you knew from the get-go who she is."

"...Yes," Muzan replied, not entirely sure where this was going, "I don't see your-"

"If you knew ahead of time who she was," Aizawa went on, cutting Muzan off in the process, "Why didn't you tell us her name the moment you were brought in?" Gesturing to where the dried blobs of cement that used to of held the now vanquished Shinobu and Rengoku currently sat, Aizawa went on, "Because the scene of that demon girl's head rematerializing, hissing, then flying to the demon guy's face to eat said face will be forever engrained into my nightmares."

Muzan looked meek before turning his head away. "...I was too scared to think straight."

Hands on his hips, Aizawa went on, "And what's this about All For One's true goals involving fighting against a secret vampire convent?"

"I... kind of want to know that myself," Toshinori admitted, "I mean, it's not every day that one hears of All For One getting up to something that sounds just plain silly."

"You..." Sekijiro began, "...You do remember how we had recently averted a zombie apocalypse, right All Might? If zombies turned out to be a real thing, then why not vampires as well?" Gesturing to Muzan, the Blood Hero went on, "Also, we apparently have demons now. Who knows what all else might await us in the future?"

"Instead of worrying about the future," Hizashi began, "We ought to worry about the here and now. We need to go stop that Nezuko bitch and prevent whatever it is that she has planned. Because if we don't, then Muzan will be in-"

Two more demons broke into the room everyone was in, startling all of them. One was blonde, wore a yellow kimono top over a standard black Demon Slayer uniform, and carried a yellowish Nichirin Sword. The other wore no top period, the leggings of the Demon Slayer uniform, a boar head mask that covered the whole of his head, and carried a pair of serrated Nichirin Swords.

"I am Zenitsu Agatsuma, and my partner here is Inosuke Hashibara!" the blonde demon declared, "We're here to kidnap Muzan!"

"Not so fast!" Cementoss said as he raised his hands, "I-"

"Whacha!" Inosuke yelled, cutting Cementoss off as he kicked him away, preventing him from using his quirk to trap the newly arrived demons.

Zenitsu then rushed Muzan, knocked him out with a punch to the gut, threw him over his shoulder, then fled with the captive progenitor of demons as Inosuke caught up to him. Looking to everyone, Hizashi said, "Bros! We need to rescue Muzan!"

"Why'd we let him get kidnapped in the first place?" Hound Dog asked, "I mean, we were just standing around like idiots!"

Pointing in the direction the demons fled in, Hizashi went on, "So the plot can continue! Now let's go after them!" Everyone left to chase after Zenitsu and Inosuke, aside from Toshinori who had to stay to keep an eye on Kirishima and Tetsutetsu.

END, CHAPTER TWO

Author's notes;

Here we see more Demon Slayers from long ago having been resurrected as the very things they had trained to kill, with Zenitsu and Inosuke showing up to kidnap Muzan and spirit him away in order to drive the plot along. Anyway, the story will continue into the next chapter, so don't turn that dial just yet.