Summary: M-21's tattoo disappeared when he developed his claws. But it wasn't gone.

Contains: Some gore.

Sentient tattoo AU!

Thanks to madameazzure for all the help with poking at this. :D

Tattoo

By Dark Ice Dragon

M-21 huffed, scratching the back of his hand.

"Still itchy?" M-24 said, handing him a cold bottle of water.

"Yeah," M-21 said, glowering at the welts he'd left before pressing the bottle to his skin. "Didn't think that would be a side effect of the transformation." They'd only heard scientists' excited whispers about the other experiments' transformations - but of course the scientists would be interested in what it meant, the progress, rather than how it had affected the experiment.

It had only been his nails that had transformed though; his skin hadn't changed. But maybe that would be what transformed next? M-21 curled his hand to see his nails better, studying them. They didn't look any different. "Still can't believe I did that," he muttered. Him. He could transform. One of the failures.

M-21 frowned at the prickling feeling over his wrist.

M-24 sucked in a breath and M-21 glanced at him. M-24 was wide-eyed and staring at his hand.

"What?" It hadn't transformed; he would have felt it.

"I..." M-24 furrowed his brow and then shook his head. "I thought I saw something."

M-21 turned his hand over and pulled back the remnants of his sleeve, but it looked the same as it had before, aside from the speckling of blood spray.

Hn. Maybe it had been a trick of the light. But they should clean themselves up before they drew attention to themselves.

[-]

M-21 stared at his wrist, watching the water flow over it. Over the unmarked skin.

"The fuck?" he said, his words echoing in the toilet. He had to be imagining it. He ran his fingers over where his 21 brand used to be, as if he would be able to feel it instead. But it had only been ink - he'd never felt any bumps when it had been there.

He couldn't have washed it off.

Had it...disappeared when he'd transformed? He hadn't thought to check it, because why would he need to? It had always been there. That was the point.

The scientists would notice and they'd mark him again. ...What if it was because of that they found out he could transform?

The back of his right hand itched again and he glowered, turning it over. Itchy skin, disappearing tattoo... Was that worth it for power? It was manageable for now, but if he got stronger, would the -

M-21 froze. Right where the tingling was, was a dog. A tattoo. It was a small and simple design, just smaller than his palm.

And it fucking moved.

It dashed around his hand, and M-21 could feel it passing over his skin. Was that what he'd felt earlier?

"Is that..." M-24 tracked the dog as it looped M-21's wrist, trying to stay out of their gaze. "Is that your tattoo?"

"It has to be?" Even though it made no fucking sense. But his tattoo was gone and now there was a dog running over his skin.

M-21 put his left hand in its way to see what it would do. It should slide underneath but - "Sss - fuck!"

He shook his hand out of instinct, but the dog stayed on his left hand. It had jumped from one part of him to another.

"It's got a '2' along its back," M-24 said and M-21 squinted at it. The long continuous line from its neck to the tip of its tail did look like a 2, and M-21 didn't know how many lines his tattoo had been, but it did look like it was around the same number making up the dog's body.

"So my tattoo became sentient?" M-21 grimaced. He couldn't let the scientists see it, but it wasn't like he could fucking control what it did. Could he be fast enough to cut it out? Or maybe if he tried to do that, it would go under his skin. Urgh.

"Oi," M-21 said, bringing his hand closer to his face. "Can you understand me?" The fuck was he doing trying to talk to a tattoo? It didn't have ears, but he was desp-

The dog turned towards him and sat.

Well, shit. It could hear him.

"Can you turn back into the 21?" M-21 asked.

The dog tilted its head.

Great. It was just a stupid dog.

"Hmm." M-24 was studying the tattoo. "Does it know what a 21 is?"

...Shit. It was a stupid dog - of course it didn't know what numbers were.

M-24 leaned closer and the dog's tail flicked in and out of sight. "Can you back into your old form?"

The dog jumped and in a swirl of ink, it turned into the image M-21 was far more used to seeing.

"Thank fuck," M-21 muttered as the dog changed back. "Do that whenever we-" It was a dog. It wouldn't understand what a checkup was. "-see the people with the white jackets. Go back to my wrist and stay there. They can't see you, understand?"

The dog barked and M-21 felt his skin vibrate. It was the weirdest fucking feeling.

They would have to see if it really understood that, but they might be able to train it before they had another checkup.

[-]

M-21 felt the dog running up his neck and he grimaced, rubbing where it had been. He and M-24 had bought a few things to eat and had sat on a rooftop, away from the crowds. As soon as they'd unwrapped the food, the dog had dashed from his hand to his face in the time M-21 had taken a bite.

"Don't go into my mouth," M-21 said. He didn't know if it could, but he didn't want to find out. The feel of its paws on his skin was weird enough - he didn't want to feel it on the inside of his mouth too.

Could it even eat? How the fuck would he feed it?

It stayed on his cheek though, and M-21 felt a rhythmic tapping instead. It was a harder impact than its paws but M-21 had no idea what it was. "What's it doing?"

"It's wagging its tail," M-24 said.

Was that a good thing or a bad thing? The dogs at the Union both tucked their tails and wagged them, and M-21 hadn't seen them enough to figure out what their behaviour meant.

But so long as the dog didn't try to get inside him while he was trying to eat, M-21 didn't care.

"Do you think it's hungry?" M-24 asked, chewing as he watched the dog run around M-21's face.

"Are you going to try and put your sandwich in my skin?" M-21 said with a snort.

M-24 shrugged, holding a piece of it towards the dog.

It barked, making M-21 grimace and then ran towards M-21's mouth. "Hey!"

It ran a loop around M-21's lips and then barked again.

The sandwich hovered over the dog and the dog kept dashing back between the sandwich and M-21's mouth.

M-24 frowned and then leaned back. "I think it's more concerned with you being fed."

M-21 rolled his eyes. "I can feed myself." Which the dog could see clearly. M-21 took another bite of his sandwich.

The dog wagged its tail again. Weird tattoo dog.

[-]

M-21 hissed, holding himself up against the wall. He could feel the dog circling the slash on his arm, the constant vibration that M-21 had learned was it barking.

"I know I'm fucking injured," M-21 snapped, glaring at it. "I can feel it, so shut the fuck up already."

The dog curled up at the tip of the slash and leaned in.

"What the fuck are you - are you fucking licking it?" He could see a flash of a tongue every second or so.

M-21 sucked in a breath. The wound felt...weird. It was hot, but it wasn't as intense and grabbing his attention as it used to be, and while he watched, the wound started sealing up. "The fuck?"

It was probably his healing kicking in but...the other end of the slash wasn't closing up.

"Is that you?" How was it doing that?

The dog barked at him before going back to licking the wound again.

"...Okay," M-21 said, not sure how to make sense of an ink tattoo helping to enhance his healing. "You keep doing that."

He had to find M-24 in the aftermath of the fight. They'd been split up, but he could hear fighting in the distance, so he knew where to head.

[-]

M-21's heart thudded and normally when that happened, the dog settled over it. It would curl up and rumble and that somehow made M-21 feel calmer, but it couldn't do it now. They were in a lab to hand in the package they'd collected, and the dog was back in its 21 shape on his wrist. For now. M-21 felt it quivering there and M-21 was sure it wanted to run around like it usually did.

He wanted to grip his wrist, even though he knew that wouldn't help. It wouldn't hold it in place, and it would draw attention to what he didn't want. He had to keep his hands by his sides as he walked through, trying to not grit his teeth.

The hairs at the back of his neck prickled and he could feel M-24's eyes on him. "I'm fine." It was a lie and they both knew it. "I just don't like it." He didn't like having control over a situation. With M-24, he could tell him something and know M-24 would try his best to follow it. He couldn't trust the dog could keep still enough to stay unnoticed.

It liked to wander around M-21's skin, peering out at whatever was uncovered. It had barely been five minutes and the dog was already trying to move.

He just had to get out of there as soon as he could without being suspicious.

[-]

M-21 exhaled, his hands shaking now that he didn't have to keep them still. "Hey," he said, pulling back his sleeve, "you can move again."

The dog sprung back to life, dashing circles around M-21's wrist. That was how M-21 felt, but if he'd ran away from the lab, the scientists and guards would have noticed.

The dog paused on the back of his hand, and M-21 watched it as it looked at him.

"What?" It looked like it was waiting for something. ...Though, M-21 had seen other dogs being walked by humans and... "You did good?" It had, hadn't it?

The dog's tail became a blur, slapping against his skin.

So that had to mean it was happy?

The dog started dashing around again, up M-21's arm to go down his other one. It felt weird, but he'd gotten used to it.

[-]

M-21 jerked awake, straining his ears for whatever had woken him.

His skin tingled instead and he stifled a groan, not wanting to wake M-24 up.

He brought his hand close to his face, scowling. The dog was there, jumping between his fingers. "Stop it."

The dog froze, its ears flattening.

"You're keeping me up."

M-21's skin buzzed but he didn't know what that meant yet.

The dog curled up on the back of his hand and stayed there, looking at him.

"Yeah, stay there until I wake up."

The dog flashed its tail before curling it around its body, closing its eyes.

Good.

M-21 closed his own eyes and fell asleep again.

[-]

M-21 woke up with a sigh, hearing M-24 already awake and moving. Sunlight was peeking in through the broken window, the morning air swirling in. That sleep hadn't been too bad. No nightmares, at least.

As soon as M-21 got up, the dog shot up his arm, climbing up to his face. "You were waiting for me to wake up?"

He got a bark in return, and he had told it to do that.

"Fine," he said. "Thanks."

He didn't need to see or feel his tattoo to know it was wagging its tail.

[-]

M-21 grunted when his back slammed against the tree, scrambling out of the way of the follow up punch. The tree splintered from the impact.

Shit. M-21 was durable, but he didn't want to be hit by that. Not again.

The agent was shouting something but the words were echoing in and out of the high pitched buzzing in his ears.

Concentrate on his hands. The claws.

They grew faster than they used to and M-21 lunged at the agent, stabbing him through the chest. He yanked the claws across with a spray of blood, feeling them catch on the ribs before slicing through them.

The agent staggered, mouth gasping as he clutched the wound, hands bloodied in seconds.

M-21 grabbed a fistful of the agent's hair and tore out his throat before the agent could react.

He almost beheaded him and he let go before the weight of the body tore itself from what was left of the neck.

M-21 panted, letting go of the transformation. That could have gone bet-

He froze, his neck pulsing. The dog was barking at something. It didn't do that often.

He dived, gritting his teeth at his protesting muscles. But sore muscles was better than being shot in the fucking head, the gunshot echoing around him as soon as he'd moved.

The dog had been on his left, but he didn't need that to guide him, someone crashing through the undergrowth away from him. To get a better vantage point to shoot him or to get help, it didn't matter.

They had to die.

His head was swimming from the fight and the transformation, but he forced his screaming muscles to work. Just a little bit more. So long as there wasn't any other backup, he just had to keep going for a little bit more.

M-21 chased after the agent, gaining ground even though he was stumbling just as hard through the undergrowth. He skidded to a halt, seeing M-24 in front of him, his eyes glowing faintly as he stood in front of the other agent.

M-21 smirked as he regained his breath, seeing M-24 reach over while the other agent stood frozen, caught under M-24's power.

M-24 reached over, wrapped his hands around the agent's head, and crushed their skull.

"Is that everyone?" M-21 said, straining his ears over his roaring heartbeat and harsh breathing. The dog had nestled over his heart and he could feel it calming down with every beat.

M-24 nodded, his eyes going back to normal as he let go of the agent.

"Good." M-21 closed his eyes and exhaled. The mission had ended in shambles, but they should still be able to collect the documents, so long as no-one else had tried to steal or destroy them after the chaos. "Thanks for grabbing them." He might not have caught up in time.

M-24 smiled at him, wiping the blood on the agent's clothes. "You flushed her towards me."

Hn. They did work well as a team. And not just M-24. "Thanks for looking out for me too," he said, tapping his cheek where the dog was staying. The dog wagged its tail. "I would have died from that." Enhanced healing or not, he couldn't survive a headshot.

M-24 sucked in a breath, his eyes wide.

"I'm alive," M-21 said, straightening, "obviously. We need to get moving though." They needed to complete their mission before anyone else arrived.

"Yeah..." M-24 followed as M-21 led the way.

[-]

M-21 sighed, the dog running laps around his body as he and M-24 stepped off the boat to arrive in South Korea. The dog had learned to stay out of sight of unmodified humans, but it made up for that by running everywhere under his clothes. It was a weird feeling but he'd gotten used to it over the years.

It was going to be a quick retrieval mission here. If nothing went wrong, they'd be able to leave the cramped city in under a week.

There's at least another two scenes I want to write, but they didn't fit in with the current feel of it, so I should add those in later.

Inspired by this post: thatmightyheart tumblr com / post / 188115687282