Third person pov

Once the symbols were painted, it was time. The ocean seemed to note this, water beginning to rise up towards the edge of the boat and slosh over as though it were aiming to grab them and drag them in. Hitoshi Shinso sealed the jars of paint back up, standing up straight and stretched. He looked notably well rested, Nezu noted. Far less tired than he usually did. Nezu didn't keep as close an eye on the students in General Education. Despite this, it was quite obvious the purple-haired boy had been doing better since Atlantis' came here. They truly didn't look alike in the least. Were they really cousins, or were they simply bound by this oceanic anomaly? 

The sea creatures continued to circle. Atlantis took a deep breath. It was time. He was nervous. This was a big secret, and he didn't want to be forced to run if it got out and people came for him. Shota was scared too. He didn't show it on his face, but Atlantis could feel it swimming in the pit of his stomach. Atlantis was confident, though, despite the odds. This Nezu fellow seemed he could keep a secret, and Recovery Girl was a kind woman. Toshinori also seemed quite esteemed, and he would surely feel indebted to them should they succeed in this ritual. Hopefully that would be enough to convince him to keep the secret too!

"Are you ready?" Hitoshi asked, coming up next to him. He looked excited, his purple eyes shining with the same awe they used to hold when he was younger. Atlantis was happy to see the familiar emotion present in his cousin's eyes. He was glad he didn't have to do this alone. He wasn't sure he'd be able to. Hitoshi being a Siren meant he was adept at discerning what the ocean wished to say. Atlantis didn't have that ability.

"If you are." Atlantis nodded. He glanced back at everyone, who watched them intently. He would've felt more embarrassed were he not so focused. He went through the motions in his mind over and over again, noting what he and Hitoshi were going to have to do and how they were going to do it. His eyes met Shota's, and he couldn't help but smile. When he thought too hard about all he'd gone through recently, he almost couldn't comprehend it. He was married and living on land. He worked in a school for human children! He'd found his long lost cousin and was now using his abilities to help others. It was... it was amazing, honestly.

The ocean began to sing, telling them it was time. The creatures all spiraled below, creating a massive circle that they'd be right in the middle of. They sung their own songs, audible only to Atlantis and Hitoshi. A part of Atlantis wanted to close his eyes and simply listen. He knew they couldn't. Time was of the essence. Mr. Toshinori was ready, and so were they. Beating around the bush at this point was going to get them nowhere fast.

"Anything you see today is expected to be kept a secret." Aizawa reminded, voice stern as he scanned over the faces. Nezu gave a nod, sipping at his tea. Recovery Girl and Toshinori bobbed their heads as well, but with far less surety. "This isn't something that can get out to the public. It would but Atlantis and Shinso both in danger. Do you understand?"

His eyes flashed red, and the nods were a little firmer this time. Atlantis smiled, looking to his cousin. Hitoshi pressed his lips together firmly, nodding. His heart was pounding with anticipation. He could practically feel the massive drain he would experience after from this. Both he and Atlantis would be weak and vulnerable. He hoped, for this reason, that the people here really were trustworthy. He wasn't sure what he'd do if his cousin was ripped away from him again. Hitoshi was somewhat safe due to his current lack of a tail. Atlantis, though... they could simply rip his necklace off and reveal his true form at any given time. That was a huge vulnerability that he wished they didn't have to share.

"Now, now, Aizawa. You know you can put your trust in us." Recovery Girl scolded lightly. She looked a bit more relaxed now, even with the boat's rickety movements. "We won't breathe a word. Right, dearies?" 

"R-Right!" Toshinori choked out. Gang Orca gave a firm nod, looking like he was about to explode from happiness when Hitoshi gave him a weak, awkward smile. Nezu gave another nod, oddly quiet but still smiling. Aizawa scanned over them critically before nodding. Atlantis gulped a little, nodding back.

He was scared. He wanted this to go well, but this was a big deal. He was one healer. A ritual like this used several. Hitoshi was so young, too. Normally there were at least two or three sirens doing this sort of thing. Not a single one who hadn't had the chance to be taught the ways of his class. He knew the ocean would act as a guide and help them as much as possible, but there was only so much it could do for them before they had to start channeling the energy themselves. Atlantis hoped they were enough. Hitoshi was determined. They'd both braced themselves for this, and Atlantis felt fairly sure they could pull it off. He just... he couldn't help but have doubts.

Hitoshi gave his cousin one last look before allowing himself to fall backwards off the back of the boat. No hesitation whatsoever. Even Aizawa looked a little surprise to see him flip so quickly. Atlantis gripped the crystal in his hand, taking a deep breath and pulling it off swiftly. He handed it to his husband, giving a small smile before falling backwards much like Hitoshi had. His tail formed as he fell towards the sea. Hitoshi had been lifted above the waves, standing firm and a little sad. They'd have to figure out how to get his tail back soon. It couldn't possibly be healthy for him to be away from it for so long.

It felt like his lungs were opening up as his tail formed. Almost as though he'd been suffocating before. The animals chittered as he dove deep into the center of their circle, a laugh losing itself in the waves as it escaped him. His tail shimmered just as it had before, happy to be free again. Atlantis allowed himself just a short moment to stretch and twist around before he rocketed back towards the surface where Hitoshi was waiting for him. A few smaller fish raced after him in a playful manner, awed by his presence and his magnificent tail. Atlantis couldn't contain his grin as he breached the waves, his gills working overtime as though they'd never work again if they stopped.

A pillar of water rose from beside Atlantis as he lifted himself a little higher, shooting out towards the boat. The faces of those who'd come with them gazed down at Hitoshi and Atlantis with wide, stunned eyes. Their expressions conveyed that this was by far the last thing they'd expected. Shota was the only one taking it well, smiling with a sort of relief at the sight of Atlantis's tail. He gripped the necklace hard in his hand, the band wrapped around his wrist so he wouldn't accidentally drop it. 

Toshinori was too taken aback to do much of anything as they ocean came up and quite literally grabbed him. Though terrifying, the pillar of water was careful when it took him. It wrapped around him like a cool hug, tugging him over the edge and lowering him towards the center of the sea life. He couldn't bring himself to focus on the numerous fish, dolphins, sharks, and other creatures. His eyes were focused on Atlantis' tail. It waved lightly beneath the waves, allowing him to tread and keep his upper half out of the sea. 

Nezu connected several dots at this moment. He realized he had been too narrow in his thinking, because of course Hitoshi Shinso and Atlantis Shimura weren't human. When you thought of them as another series, the possibilities were broader. He had always know there were other forms of life. Look at him. He was, physically, an animal. One that was not a human-animal hybrid. Biologically, he was 100% albino Stout. Quirks developed so abruptly, and their causes were completely unknown. To assume there were other sorts of life out there-- such as merfolk-- was far from a stretch.

It was otherworldly, really. The water soothed the pain of his scar immediately, and the painted symbols began to glow as he was lowered towards the circling sea life. It was intimidating to look down and see so many creatures-- some dangerous and some not-- spiraling in such a specific formation. The longer he gazed, the more mesmerizing it became. His heartrate began to slow as his eyes followed the movements. He had to turn more to see everything as he was lowered, his body twisting as best it could to try and take it all in close up. 

He could hear music. Or something. He didn't know. He was too distracted to really think too hard about it, his eyes instead coming to rest on Atlantis' tail. It was a sparkling blue color that reflected light under the waves. Lean and powerful, with transparent fins that almost seemed to glitter when light hit them. It was a different type of majestic he'd never gotten to see before. Like a dance, but not at the same time. This seemed prettier and far more reverent. It felt almost like he should bow his head. He couldn't bring himself to. He was too overwhelmed. There was too much goin on that he felt like he had to see.

In all honesty, he'd been scared. He still was. Atlantis Shimura was mysterious, and the implications presented before him now edged towards the believe that the man probably wasn't human. If he shared the same name as his late teacher, what did that mean? Were they related-- had Nana been one of these beings too? He didn't know what to think or how to feel about this. He felt so at peace, yet somehow so out of control. It was like he was sinking and didn't have the energy of knowledge on how to fight back. It was something inevitable that he simply couldn't stop.

Atlantis' hands came up, and Toshinori blinked when he realized the man was in front of him. It was oddly quiet for how tremulous the waters were. Water snaked up out of the water, glowing a brilliant color that drew him in and left him breathless. He watched with wide eyes as it came towards him, wrapping around his limbs. The symbols on his chest heated-- but not an uncomfortable amount. Toshinori realized, vaguely, that they were glowing too. The feeling pierced him and consumed every nerve in his body. Not uncomfortably, but it was far from his favorite sensation.

"It's going to be okay." Atlantis promised, his eyes earnest. Toshinori thought maybe he saw his teacher in those eyes. Atlantis reached out his hands, smiling. "Trust us."

So he did. He offered his hands forth too and forced out a nervous smile. The creatures below swarmed, and Young Shinso began to hum. It was not a normal noise. It was low and unnatural-- not a sound any normal human could make. It almost didn't sound real. Toshinori didn't look towards the purple haired boy. He kept his eyes on Atlantis', struck by their glow and honesty. They were like a pair of open books. Toshinori wondered how he hadn't noticed before. Had they always been that way? Was this new?

There was a blinding light that took him by surprise, engulfing him. Young Shinso was chanting something loud and booming. His voice was like thunder. Atlantis' eyes were so bright they looked almost white. The sea creatures drew in closer. 

And then, there was nothing.

~~~~~~~~~~~~~~~~~~~

Shigaraki couldn't stop scratching.

He'd been agitated all day, and he didn't know why. He clawed at the sides of his neck. His skin was impossibly dry and horribly itchy. He didn't know where the habit of scratching his neck came from. It simply felt like there was something there that was missing. It irritated him. Everything did these days, but today especially was hard. It made him even more annoyed that he couldn't find the source of his agitation. It wasn't something he could kill or turn to dust. There was just something in the air that was calling to him. Calling to him for what? What did it want? Why did he want to follow it?

"Tomura Shigaraki." Kurogiri's cool voice broke through his train of thought, and he stopped scratching abruptly. "Something appears to be bothering you."

"Yeah, no shit." Shigaraki bit out. He didn't mean to. He wasn't trying to. He quite liked Kurogiri, and snapping at him wasn't something he wanted to do. He couldn't stop himself. He constantly felt agitated. Despite his viciousness, the warp-gate user did not so much as flinch. He simply stared at him in an indifferent manner. Tomura wished he could be indifferent too. He wished he could turn his emotions off and simply exist in nothingness for a time. Anything would be better than this pull. He couldn't tell where it was coming from or how to follow it.

Or maybe he could. It was raining today, and he wanted to leave. It was strong. The thing called to him. He didn't know if this happened to other people, or if it was just him. It was something he'd always felt. He couldn't remember his childhood, but for as long as he could recall, he'd always experienced this weird tug that never let up in its persistence. He'd thought for a while it was a mental illness, but it didn't feel wrong. It felt almost alive, and it filtered emotions that were not his own into him. Like another being pushing its sentiments into him. He wasn't sure whether or not he liked it.

Kurogiri watched him carefully, considering. He knew the rules. He knew under no circumstances was he meant to take Tomura Shigaraki anywhere near the sea. Why, he did not know, but it was becoming increasingly clearer that it probably related to why Tomura was agitated. The young man barely spoke on it, but sometimes he mentioned needing to go somewhere. When questioned where, he'd become morose. Like he was missing someone or something, and he'd admit that he did not know. He had no idea where he was supposed to be going. Kurogiri wondered if maybe this place was the ocean. And if maybe... maybe taking him would help.

"Tomura..." Kurogiri trailed off, his voice a wispy echo. Tomura looked at him, and his weak doubts washed away at the uncharacteristic sadness. He wasn't supposed to care. He knew that. But he couldn't help it-- not after he'd practically raised the boy from the moment he came here. "Would you be willing to go somewhere with me? I feel I may know what you're looking for."

Tomura brightened considerably, though that wasn't by much. It was answer enough for Kurogiri anyway.

~~~~~~~~

There's another mermaid that hasn't been revealed yet (: They're a canon character that has only been mentioned in the story once, but not in any relation to the merfolk. Can you guess who it is? They're a different class than any that have been mentioned before, but if I told you what that class was it would give it away immediately. I'll be super impressed if anyone can figure it out