You know. It's funny. I never expected this fic to get popular. Let alone be my most popular fic by a long shot.

Then again, I am always bad at predicting what will be popular.

The Strongest of Them All, The Hero We Need, and A Hero is Made are all fics I put a lot of effort into and wanted them to get popular. And they are my least popular fics.

This, Spirit of Vengeance/Izuku the Ghost Rider, and Mechanical Evolution were all experimental fics, most of them I planned on deleting. They are my most popular fics.

I just...I don't understand?

Anyway, so this chapter introduces the first submitted O.C.!

Credit to Remzal Von Enili for the O.C. Mu!

Now just as a reminder, once an O.C. is in the story, they are in my hands. I will go by whatever was agreed on in the P.M.'s but other than that I have free range.

So, with that said, onto the fic.

Izuku was glad that, at the very least, two of the three new children would not require any special precautions.

Mu was an...interesting one. His quirk let him phase into a different dimension. Now it wasn't like he went to a different universe or something, reportedly, it's more like he went to a different plane of existence, where he could still see everything around him, but they can't see or interact with him, and he can't interact with them. In fact, he could reportedly go through objects while in this dimension, and even walls.

One big drawback, however, is that wherever or whatever this dimension is, it doesn't seem like things are really supposed to...exist in it. And as such, if Mu stays in that dimension for any time after thirty minutes, his body starts to break down and disintegrates. Then it takes about an hour before he can safely re-enter his dimension.

He can also drag other things and even people into this dimension, however, they break down much faster, typically after about a minute.

Also, according to the reports, the boy was rather shy and liked to be in his dimension for long periods of time, often he wouldn't realize when he should leave his dimension until he had already started disintegrating, leading to various health issues.

So in other words. Izuku now had a ghost child whom he could not see or touch and could walk through walls, as well as being able to destroy basically anything he could physically drag into his dimension...oh and he also had to somehow make sure he didn't accidentally kill himself by overusing his quirk. What fun.

Yonda, on the other hand, had a quirk that didn't pose a physical threat, rather it was a threat to people's privacy.

Her quirk was a rare quirk that gave her a disability, making her completely deaf and mute. Instead of hearing words, she could hear people's thoughts, as if they were speaking them out loud. And instead of speaking, she could communicate telepathically.

Interestingly enough, her telepathy worked more like talking but in people's minds. The range of her ability only extended to hearing range, however it was unaffected by walls and other obstacles.

Hopefully, he could keep from thinking anything worrying or complicated around her. Although that would be difficult. He'd also told all the kids about this of course, so that way they would at least know what was happening.

The last child did require a custom room. Little Netsu had a fire quirk. A really powerful fire quirk. One that he would have a rather hard time turning off. As a result, the boy was always on fire. Meaning not only would he require a special room, but he would also need special clothes as well as gloves and shoes, and he would need way more fire extinguishers around the house...and he would need to teach the kids how to use fire extinguishers. They had a sprinkler system, but he didn't want to take chances.

Well on the bright side he wouldn't really need to wash his clothes considering any filth would almost certainly get incinerated by the constant fire. Not that his job of washing everyone's clothes would get any easier.

Izuku sighed as he waited outside the house for the new arrivals. He had stopped trying to get the children altogether for the new arrivals, as that was a fool's errand at this point. They would eventually meet up with each other...hopefully. Fukunoko still hasn't met half the houses' residents.

He was brought out of his thoughts, by the sounds of cars pulling up around the tree.

Eventually, the cars stopped, and then someone stepped out.

It was Namae.

Oh no. Izuku's shoulders slumped. Seeing Namae was never a good sign.

And what's worse, is that she was holding a weird metal canister. Which gave Izuku all sorts of bad feelings.

"Izu! My dude!" Namae said casually, walking up to him like her existence wasn't a blight on his sanity. "How are you! Are you getting some help? Like...mentally...and physically?"

"I'm looking into it," Izuku said, his tone completely devoid of energy. "Not to be rude, but, why are you here? And what's in that canister."

"Ah, don't worry bout that!" Namae waved her hand dismissively in an exaggerated fashion. "Let's get these kids inside and then we can have a little chat."

Izuku looked towards the car and saw two men walking towards him, carrying an unconscious boy in their arms.

He was about seven and pretty small for his age. His entire body, as well as his hair, was bone white. Really giving off a ghostly vibe. This was presumably Mu.

They dumped the boy in his arms, and Izuku noted how incredibly light he was.

"We sedated him so that way he didn't use his quirk while we were transporting him," Namae explained.

"I hope this doesn't become a pattern." Izuku sighed, remembering how Fukunoko also came here unconscious.

Hello father. Said a feminine voice in his head.

Izuku panicked for a moment, before realizing who this was. Oh, you must be Yonda! Nice to meet you.

A pleasure. Yonda said, stepping out of the car to reveal herself to him.

The girl was about nine years old, with curly pink hair that had some purple strands in it, and her eyes were also a strange shade of pink.

Adorable as expected. Was Izuku's reactionary thought. They all are.

Thank you! Came the girl's cheery thought, as she smiled brightly. Izuku noticed that despite no words coming out, her mouth still moved when she used her telepathy.

Oh, right she can hear me! Izuku thought as he realized just how hard it was gonna be to control his thoughts. Thank goodness I don't curse even in my head.

I already know a lot of bad words. Yonda thought sadly.

Oh. Izuku slumped.

Then from the last car, came an agent who was sweating profusely, panting for air as she looked like she had been in the sauna for too long.

"Why-why didn't I get protective equipment!" Asked the woman. "We're here! Get out! Please!"

The back door opened, and then-

FWOOSH!

A fireball burst from the car and went up six feet in the air, burning so bright they all had to look away for a moment.

"Behold! I have arrived!" Shouted a small boy's voice.

When the light died down, they could see a small boy, about seven years old, his body a burning red inferno, with flames crackling off of him, contained by fireproof clothing, floating six feet in the air. Netsu.

Oh, I have a bad feeling about this. Izuku thought, not seeing Yonda nod after hearing his thoughts.

Netsu looked down at Izuku, and they could make out a smirk behind his flames. "So you're my new father. Well, congratulations! You just hit the jackpot! The great Netsu has appeared! Soon to be the world's greatest hero!"

He and Kiba are going to fight. A lot. Izuku realized.

Who is Kiba? Yonda asked.

Oh, she's another one of the kids...trust me. You'll know who she is soon. Izuku responded, before turning his attention to Netsu and putting on an uneasy smile. "Well, could you come down so we can go inside and I can show you your room?"

"Uh...yeah just…" Netsu stopped talking and started focusing.

His body started going down a few centimeters, only to float back up.

He can't get down, can he? Yonda asked.

Maybe. Izuku watched for a few more moments, however, the boy simply could not get down. No, I don't think he can.

Idiot. Yonda thought, however, she didn't use her telepathy so Izuku didn't hear that one.

"Do you need some help?" Izuku asked him.

"N-no! I got it!" Netsu kept trying but after a few moments, he slumped over dejectedly. "Please get me down."

Izuku nodded and started looking around in his pocket, before finding what he was looking for. A white, bone-like whistle.

WEEEEEEEW!

From the top of the house, a Grimm griffin heard the whistle, and flew down, eventually landing in front of Izuku. Freaking out Yonda.

What is that! The small girl immediately ran behind Izuku, hiding behind his leg.

"Cool!" Netsu said with eyes wide in awe.

"This is a Grimm. One of the other kids here makes these to guard the house and help the others." Izuku explained, going up to the creatures. "So even if they look scary. Don't be afraid of them."

Izuku made sure to think about everything he was saying, word for word, so that way Yonda could hear what he was saying.

Yonda still looked at the beast skeptically, still unnerved by the monster made of darkness.

"Please help him down, gently," Izuku ordered the Grimm.

The griffin flew up and grabbed the boy's leg with his claw, fortunately, it grabbed his pants so the fire didn't spread to it as well.

He pulled the boy down to the floor, before promptly letting him go.

"Ah yeah! Thanks, demon bird!" Netsu said with a big grin on his face.

"Alright, go back to the roof with the others," Izuku ordered, as the Griffin followed his orders and flew away.

Others? There are more of those things? Yonda asked.

Yeah, but they're not all over the place. I try to keep them out of sight most of the time because they are...a bit scary. Izuku thought.

A bit? Yonda thought.

"Can I have one of those!?" Netsu ran up to Izuku and asked with eyes wide in excitement.

"Well, all the kids can ask the Grimm for help," Izuku explained. He did ask Yami to give the kids control of the Grimm as well, albeit limited control. He didn't want Kiba to order the Manticore to start shooting fire and end up setting the house ablaze. Although with Netsu that was now going to be a constant concern. "But if you're good you could have one for a pet."

"Yes! My new dad is awesome!" Netsu cheered.

Izuku felt a spark of happiness in his chest from that statement, and a small smile appeared on his face.

Seeing this Yonda scowled for a second, before hugging Izuku's arm. I think you're great too dad!

O-Oh! Thank you. Izuku told her mentally. Wow. The kids sure do behave well. Then again none of them ever really behaved badly. I mean...Yami kidnapped me but he didn't know any better.

What!? Yonda's eyes went wide with shock after hearing that.

Oh, right she can still hear me! Izuku realized. Uh, don't worry about that. I'm fine. He's fine. He didn't know any better at the time! He won't do anything like that again!

O-ok. Yonda didn't seem fully convinced.

Hopefully meeting him will help get rid of some of her fears. Izuku thought, before realizing once again she could still hear him. I'm just gonna have to get used to this, aren't I?

"Hey what's that voice I'm hearing in my head?" Netsu asked. Hello? Voice? Who are you?

That's me. Yonda said, raising her hand. It's my quirk. I can hear your thoughts too.

"Wow! Ok, what number am I thinking of!?" Netsu asked.

You're not thinking of a number. You're thinking you're so smart by not thinking of a number. Yonda couldn't help but roll her eyes.

"Woah!" Netsu said. "Your quirk is cool! Not as cool as mine, but cool!"

I'm deaf. Yonda explained bluntly.

Oh...what does that mean? Netsu tilted his head in confusion.

It means I can't hear anything. I can hear thoughts. But not anything else. Yonda asked. So I can't hear when you talk.

Oh. Netsu thought. Ok. Your quirk is cool! Not as cool as mine, but cool!

Thanks. Yonda thought.

"Well now that everyone is introduced! Let's go inside!" Namae grinned. "The sooner you two get to your rooms the sooner me and daddy dearest get to talk."

"P-please don't call me that." Izuku sighed, pulling out a thermos and drinking coffee. So tired. Need to keep going.

Are you tired father? Yonda asked concerned for her new father's safety.

Izuku flinched. I'm fine! I'm fine! Let's just...let's go to your rooms.

Sometime later.

Izuku and Namae sat in his office, with Namae still holding the canister, and Fu having joined them at Namae's request.

The new children had been shown to their rooms and Izuku had excused himself. Yonda had tried to stick around, but Izuku insisted that they would get to know each other better after this meeting.

"Again, not to be rude, but why are you here, and why did you ask that Fu join us?" Izuku asked.

Fu was sitting behind him, staying silent and listening intently.

"Well remember when I said we were only gonna bring three?" Namae asked.

Izuku's eyes widened, as he realized what exactly was in that canister.

"Before you say anything!" Namae said quickly. "It's a baby! We brought them into our custody, and we needed to get them out of there immediately. For their safety!"

Izuku sighed. "Well...if it's for their safety then it can't be helped. Please explain more about the child, and what this has to do with Fu?"

"Ah well you see, they don't have a name yet so we just call them by their quirk's name. Symbiote." Namae explained. "They were born about a month ago, their quirk makes them this, black gooey thing. Kind of like Sansan, but if she was made of that black crap that Yami vomits."

So that's why they're in that container. Izuku thought. I hope they haven't been in there for too long.

"When he latches onto a living thing goes inside them via their pours or something, and starts what we call a bond ``." Namae continued. "When it bonds to someone, they become incredibly strong. Like we're talking about some apex predator type sh-stuff. They become strong and fast as well, they can use his black gooey body to make weapons and tendrils and all sorts of crap. They just turn into crazy strong dudes. Like if anyone made a bond with him, boom, instant top ten hero."

Namae looked at Fu. Come on take the bait kid.

"So what's the downside." Izuku knew there had to be one. There always was when dealing with O.P.C.'s quirks.

"Well you see, the catch is that it eats your organs and makes your emotions go way out of control!" Namae explained. "His mother was his first host. She had a really weird pregnancy let's just say. She didn't get a baby bump or anything, and after nine months she didn't give birth she just started acting weird, she got really aggressive, and eventually, we found out about the kid when she used him to go on a rampage. When she was eventually defeated, we found that most of her internal organs had been damaged, eaten by the kid. She passed a few days later."

Oh. I see now. Izuku finally realized why they wanted Fu here. "You want Fu to be the new host."

"Bingo!" Namae said, giving him a thumbs up. "You see, without a host, the kid will die in about a week. And we can't just keep giving him animals because the animal rights people might actually kill us if we do, and we would have to contain superpowered animals all the time. But Fu, he's perfect. One, he regenerates so the kid can't kill him so long as he keeps eating. Two, he can't feel pain. And three, the nerds over at research say that the kid won't be able to affect his brain, given that a lot of his emotional centers are, you know-"

"Dead." Fu finished.

"Yeah, he does sound like a perfect host. Getting all the upsides without any of the downsides." Izuku said, his voice carrying a bit of suspicion. "And you're sure nothing bad will happen to Fu? No negative effects?"

"Nope!" Namae said. "Nothing but positives! Besides, it's not like you have a choice. You have to take the kid under contract. So even if we put this off, eventually you'd have to take him and give him a host. And there is no one better than Fu."

Izuku frowned. It was true. Even if he wanted to refuse, which he didn't really, he still wanted to help the kid, he couldn't. And no one other than Fu could act as a host to the new kid without dying or being in constant pain."

"I'll do it," Fu spoke up, volunteering himself. "It's not really a hard decision. I get all the power and it gets to live. What's wrong here?"

"Oh...well...if you're really sure about this I guess." Izuku said. "Then there's no problem."

"Great!" Namae said. "Duck!"

Then, she promptly twisted the handle of the container and opened the lid.

"Huh? AH!" Izuku was lucky to be hyped up on coffee, otherwise, he wouldn't have been able to duck in time, as the child lunged out of the container, over Izuku's head, before landing on Fu.

Fu didn't even flinch as the black goo covered his face, before disappearing into his body. "Huh...that feels different."

"You're ok?" Izuku asked. He knew that Fu should be fine, but he was still worried because...well when was he not?

"Yeah. I...I can feel it." Fu said. "I can...hear him. He's relieved...he's getting confused by my regeneration...he's happy about it...I think."

"Well, I'll let you two get used to your new life long bond!" Namae said, standing up and going for the door. "Oh yeah, by the way, the kid has a weakness to really loud sounds and heat! So be careful!"

"Wait what?!" Izuku shouted after her as she opened the door to leave.

"You see more in the details bye!" Namae said as she quickly shut the door.

Izuku looked stunned for a moment, before shaking his head. You gave me the kid who's weak to fire. At the same time as a kid with a fire quirk!?

He hated D.O.C. sometimes...okay hate was a strong word. But he did lament their lack of competence.

"Hey, dad?" Izuku felt a tug on his shoulder.

He looked and found a slick black tendril laying on his shoulder, coming from Fu.

"We want to go test our new power," Fu said. "And tell Kiba about it too."

Izuku smiled at him. "Of course, I think she's in the training room right now."

"Great," Fu said, heading towards the door, before stopping in his tracks. "Hey, what's his name."

"Oh uh…" Izuku berated himself for forgetting something like that. "How about...Kyosei."

"Hmm. He likes it." Fu said. "It's weird...to feel feelings again. Even if they're not mine...I...I missed it."

And with that, the boy left.

Izuku sat back in his chair. Ok...back to the paperwork.

"Is he going to be ok?" Came an unknown voice from the side of his desk.

"AH!" Izuku jolted up and looked for the source of this voice.

Peeking his head out from the side of the desk, was Mu.

Now that he was awake, he could actually see his eyes. Much like Yami, the whites of his eyes were black, however, his pupils were white.

He must have been in his dimension and came up here. Izuku thought. "He'll be fine. More than fine I think."

"Oh. Ok." The boy said.

He hid his head back behind the desk.

Izuku waited a moment, before looking behind the desk, and finding that the boy had vanished.

"Um...if you're still here. You don't have to be afraid of anything." Izuku said to a seemingly empty room. "Please don't hurt yourself...you don't need to hide."

There was no response.

After a few moments, Izuku sat back down and drank some more coffee. I really hope I wasn't talking to an empty room.

Meanwhile, outside his office.

Fu gently closed the door behind him, and as he turned around, he noticed Yonda standing outside Izuku's office, trying to look nonchalant and unsuspicious.

"Who are you?" Fu asked. She's probably one of the new kids.

I am. Yonda said in his mind, surprising him momentarily. Not that it showed on his face. My name is Yonda! And you are?

"Fu." Fu introduced himself.

I can't hear you. Yonda explained. I can only hear thoughts.

Ohh. You can't turn that off, can you? Fu suspected he was about to take out his notebook to write down some notes about this when a black tendril came out and gave it to him. Thanks.

No. Yonda shook her head. So are you one of my new brothers?

Yup. I'm Fu. And uh...Kyosei's here too. Fu thought.

Is he the...thing that's making weird noises inside you? Yonda squinted at him. She could hear Kyosei, but as he didn't know any words, it was all a bunch of nonsensical noises.

Probably. Fu thought. So, you were listening to what dad was talking about? Pretty sure you are not supposed to do that.

I was just making sure he was ok! Yonda thought defensively. That woman wasn't trustable and she was carrying something that kept growling angrily in that container!

...That's fair. Fu thought.

Fu felt Kyosei urge him. He wanted to be active.

Well. I'm going to the training room. Fu started walking away. Do you want to come?

No thanks. I want to spend some more time with father. She lied slightly.

Fu shrugged and walked away.

Once he left, Yonda turned back to the door.

She liked what she was hearing from her new father. He was much nicer than practically everyone else she had met at this point.

He couldn't hide things from her, almost no one could, but he also didn't really try to deceive her. And he cared about her, and all the other kids. Which is all she really wanted anyway.

Yes, he would do nicely. This place seemed to be the place she had been looking for. A perfect home.

And she would do everything in her power to make sure it stayed like that.

Surprise! It's actually four kids! Well...three kids and a baby symbiote.

Anyway, the next chapter will expand more on the kids, this chapter was just to introduce them.

Also, I just want to explain how Yonda's quirk works. Basically, her sense of hearing and ability to speak are replaced by psychic abilities, but they also work like the sense they replace. She can't turn off her ability to hear thoughts, because you can't turn off your ears, but since it's a psychic ability that's not affected by things like walls. She can think things without using her telepathy because she has to move her lips to use it, and when she uses her telepathy, everyone in hearing range can hear her.

So, please review and have a nice day.