AN: I have a thing for soulmate AU's and for inking up Stiles. I don't know why. I have no idea why, as tattoos aren't things that I'm overly into as far as a literary device, but with Stiles...So, this is to scratch that itch.

Shield and Strength

When Stiles met his soulmate for the first time, he had absolutely no idea who he was. The mark wasn't exactly definitive where it wrapped along his shoulder as a palm print. His parents had loved it at first, pleased with the placement. Just there, the strong, tapered fingers wrapping around the front of his narrow shoulder, the broad palm against the back. His father said that it was a strong mark, one that meant they would claim him while having his back, stand beside, not in front of or trailing behind.

His mother was romantic about it. She said that it was to hold him close, the palm print possessive but loving. She was sure that it was a woman's hand, even with the broad, strong fingers and the knobbiness of the angles. She said that it would be a strong woman, that she would be perfect for his energy. His father only smiled wryly at her and eyed the darker skin knowingly.

For his first several years, they loved it; Stiles hated it.

Most of the kids at school had the classic symbols: doves or little hearts or words or even names. He never met anyone with a palm print before, and the first time the students saw it, they wanted to touch, to lay their tiny little palms against it. It bothered him every time someone's hand laid against it, made him shiver uncomfortably in the wrongness. He hated it even more because it was clear, as they grew older, that Lydia Martin had decidedly petite hands.

He hated it even more when it changed. At first, he'd been excited. Soul marks didn't often change, and it meant a fundamental change in a relationship when it happened. His mother sobbed when he showed her, and that was enough for him to hate it even more. Some days he would wake up and it would be a palm again, some days it changed over and over again throughout the day. He never really paid attention to the rhythms of it until, midway through his seventh grade year, it changed again.

Where before it was a heavy, warm brown, as though the palm there had warmed him, tanned him like the sun, now it was faint, ghostly, and it was his father that frowned down at it with upset eyes. It meant, as his high school counselor told him, that his soulmate was unreceptive to him. It was the first time that Stiles wanted to cover it up for an entirely different reason.

-Shield and Strength-

It was Derek's soulmark that got him through the fire, solid and sure, resting against his chest, a shield that went from midsternum to over his left pectoral, hiding his heart behind it. His parents had loved the mark, said that it was a strong person that left that type of mark, a deep, burned red color that was so clear in its intent that even after Kate, he couldn't hate them.

Kate had never stood between him and danger, never put herself on the line for him, and after the fire, it was clear as to why. Still, as he and Laura ran, that shield remained behind, strong and unchanging. Slowly though, as each year passed and as he grew further and further into his own head, he started wondering at that shield, if it was to keep his heart protected or to keep them protected from him.

With blue eyes and a secret buried deep to his soul, he wondered at the type of person that fate had tied to him, had forward upon him. The first time he hated the shield he was twenty-one and a girl he'd picked up at the bar told him that it was too masculine a mark to be a woman. He hadn't considered the type of person that would leave that type of mark other than a protector, someone brave, loyal.

The closer he studied it, the surer he was that she was right, though. It was a heavy style, in what looked to be iron and hardened leather and burnt steel. It didn't scare him, per say, but it was enough to make him ignore the mark completely, ignore the concept of a soulmate-because the poor bastard fate had saddled him with didn't deserve the pain anyway-and tried to move on the best he could.

The first time the mark changed, a few weeks after he'd decided that he didn't want it, Derek almost sobbed. He wasn't sure if it was in relief or mourning. The shield was still there, overlying his heart, but the clean, knightly shield had changed, growing spindly and knobbed. Thornes seemed to wrap around all sides of it, spined and angry looking against his skin.

It stayed that way through Laura, through him having to gather up the remains of her and bury her by their childhood home, and when he stood over the fresh grave, aconite stinging his hands, he was grateful for those thorns.

-Shield and Strength-

After the Peter fiasco, with Scott wolfing out for the first, time, the changing mark made so much more sense that it was painful in the pit of his stomach. His mate would be a wolf, which only meant...well. He was as confident as any seventeen year old high school student with an attention deficit disorder, lanky limbs, and a mouth that ran off without him.

So, at seventeen years old, he forged his father's signature, took the jeep two towns over, and got his first tattoo. It was simple, and just enough to be one of those vague soulmarks that people didn't think twice about. A band around his right wrist, an inch thick and barbed with thorns. He wasn't sure why he had agreed at first, but the artist had commiserated with his soulmark woes and had told him to just sit down and he'd take care of it. It was halfway into existence, an angry snarl of thorns circling his wrist. It felt right.

He ignored how it didn't make him sick the first time Derek shoved him into a wall, his hand over the real mark at his shoulder. Mostly, he ignored everything that happened concerning his real mark until Erica and Boyd, both gone because of his own weakness, his own inability to protect his friends.

The reminder of them, two sets of trailing wolf tracks, twisted up his forearm where they disappeared out of his sight beneath his elbow. The rest seemed to just come from there. Each little member of his pack against his skin, represented in the skin of his right arm. He couldn't' bring himself to touch the left, even though the print there had slowly started darkening again.

It was the nogitsune that changed that. It was the nogitsune that changed everything.

-Shield and Strength-

Derek didn't notice it changing. Everything had been so busy, so life-or-death for so long that he hadn't had time to consider anything but how he was going to get his pack through everything alive. How he was going to watch them fall apart around their own insecurities.

His shield had cracked, right down the middle, though it yet remained battered and beaten. He worried over it far more than he wanted to admit, but it again was lost in the hectic fight against a darkened part of their own that-if he were honest-made him more angry than anything else. Angry because it was Stiles, Stiles who had never done anything but try to help, try to protect the pack and keep it together, and he couldn't do anything but watch him fall apart.

There wasn't time to be distracted by a soulmate somewhere, falling apart, no matter how much it made Derek uncomfortable to know that that shield was slowly crumbling beneath the weight of something he couldn't know. By the end, when Alison was buried and Scott couldn't quite meet Stiles' eyes, Derek had time to worry about his mark, and he was shocked to find that it had broken clean in half, part of it laying down along his last rib, wrapped in vines and a snarl of brambles. The other half remained in place, though cracked and looking so very much like it might join the other half at any moment.

He feared the fallout of that other half falling, didn't want to think about what it might mean. Yet it remained there through the next year or two, little chunks falling out here or there, more vines growing up and cementing pieces back together. He was exploring South America when it happened. The other half of the shield shattered so suddenly and painfully that Derek felt it happen. Something in his own soul broke, and he was running, following the wolf, listening to it as it howled and demanded and promised pain to whatever had made that shield finally shatter.

-Shield and Strength-

Stiles didn't care that the entirety of his right arm was covered, inked with intricate little pieces of his life. It was better that way. It kept people guessing at the true mark buried in the mess, and yet no one would know that a single, solid hand at his shoulder had become a series of running prints, feet and paws alike. They'd been like that for months when it happened.

Stiles world had been falling apart around his ears for the last year, and in the rain, the last of it gave way. He'd lied in his life. He'd lied to protect his friends, his family-his pack-and while he wasn't proud of it, he refused to be ashamed. He'd…

Well, he'd killed. He'd killed a friend, and while he wasn't proud of it, he refused to be guilty anymore. He'd been a puppet, and one couldn't blame the tool for the user's actions. So, he'd fought his way back from a dark, self-loathing spiral, and then, well, then he'd killed to protect himself. He, if pushed to admit it, was a little proud of that, but he was guilty.

Since Derek had left, Scott had fallen into the role of Alpha seemlessly. He was the white knight, riding the white horse with his standard billowing in the wind. It didn't make Stiles the black knight, but it did make him the grey. The one that went into war, got blood on his hands and his cloak in the name of the defence of those that couldn't or wouldn't defend themselves.

There, in the rain, his guilt bolstered inside of him, Scott tore down whatever was left of Stiles Stilinski. Sure, there were conversations later, forgiveness and understanding, but it was clear what they would be for the rest of time. Scott would trust too openly, hold his heart and a dagger out, one in each hand, and offer both to everyone they met. It would be Stiles that would have to wrestle that dagger from the hands of his enemies and turn it on them. Scott would be shocked and disappointed, and Stiles would forever be the grey knight, a blood spattered disappointment that lost his horse and had knicks in his sword.

Through it all, he didn't notice that the trailing foot prints on his shoulder had turned around and were running back toward him.

-Shield and Strength-

When his wolf lead him back to Beacon Hills, Derek figured it had nothing to do with his ruined soulmark and everything to do with the pack, fracturing at its core. Scott and Stiles had never been more at odds, despite their careful words and the way that Stiles seemed to always throw himself into everything.

It was when his mark changed again that he knew. Stiles had been working at using his spark, and while the type of magic that most had thought of as children was beyond him, the kind that took study and research and could be qualified, came so very naturally to him that it was breathtaking.

His mark changed as Stiles did, blossomed back into his own, and Derek knew. The half of his shield was slowly etched with runes, symbols that seemed to glow out of the very soul of him. The other was completely wrapped in vines, pulled back up to his chest, those trailing brambles and plants holding it up from the base of his ribs.

-Shield and Strength-

Stiles knew. He thinks he'd known for a long time, but he never let himself think on it for too long. He knew when the prints had run; he definitely knew when the came back and that hand was again at his shoulder. If Derek was there more than he'd been before, watching everything he'd done, how he'd become something less than pure, a touch more than human, well...Stiles didn't see any judgement in his eyes.

Derek, to his knowledge, didn't have a soulmark that he recognized, and so Stiles kept his silence. Through years of learning and defending their home. Through college and break-ups and heart-breaks. Through Peter's leaving. Through John's death. Through Cora running off and coming back and running off again. Stiles figured that whatever his mark was on Derek's body, he just hoped that it had been as comforting to him as Derek's palm print had become in the last few years.

He was content to have that strength there, reminding him to stumble but get back up. He hadn't planned on Derek Hale of all people breaking down first. Of course, he should have seen it coming.

Stiles stepped out of the shower, towel wrapped around his hips and another scrubbing at his hair. It had grown longer in the last few months, something that he'd unconsciously decided to allow. He had his boxers and a pair of sweats up over his hips when his window popped open. Derek had been using the door more lately, if only because the house belonged solely to Stiles now, but old habits reared their heads eventually.

Stiles left his towel draped over his left shoulder, quietly pleased when sharp eyes flickered up over his right arm.

"Can I help you, big guy?" Stiles asked. Derek wasn't the only one with habits. Through college, Stiles had gained an inch on Derek, though he was still lanky, more wire than bulk. Derek didn't answer. Instead, he took two steps forward, gripped Stiles' arm at the elbow, and waded through the little images and symbols there. Stiles almost felt bad as he slowly let go, something like disappointment coloring his face.

"I guess not," Derek said uneasily. Stiles felt something small and cold harden in the pit of his stomach, something that felt a lot like guilt..

"What were you looking for?" Stiles asked, but Derek just shook his head and turned away. Stiles should have let him go. Really, if there was ever a time to let sulking wolves lie, it was in that moment, but he'd reached out before he even knew. Dere's elbow was in his fingers only a moment before he was spun around, slammed into his own wall, a hand against his shoulder. Against his shoulder.

"Come on, man, let up," Stiles said. There was none of the discomfort that he'd had in the past when someone had laid hands on that mark, none of the wrongness.

"Leave it, Stiles," Derek said, the command of an Alpha coloring his voice even though his eyes no longer held the power. Stiles would nearly always listen to that voice. Nearly. He struggled against the hold once more, and Derek's hand slid enough in that movement that he froze. It took a moment for the wolf to find it, the reason that he'd not wanted the werewolf close in that moment.

"This," Derek said, fingers trailing back up and into place. Stiles knew they were there, lined up perfectly. "This is mine." His hand tightened down, possessive even if Stiles couldn't see his expression.

"Probably," Stiles said. He let Derek stare at it for a minute longer before he pulled away, crossed to his dresser, and pulled the first shirt he could find over his head. "But you knew that already." Derek made a noncommittal gesture and rubbed a hand over his chest.

"Has it changed?" Derek asked.

"Every time you do," Stiles said easily. "And when you leave."

"When I leave?" he asked, and Stiles nodded.

"Turns into tracks, running. Can I?" Derek hadn't taken his hand away from the same spot to the left side of his chest. The wolf nodded and hesitated a moment before pulling his shirt up enough to expose it. Stiles had seen the shield before, when it was whole and complete. He'd liked it then, back before he even had the vaguest guess at who's it might be. Now, though, now it was a battered thing, patched together with vines and runes and more scarred than shining as it had been before.

"That's...that's my mark," he said, feeling unease sweep through him. "I'm sorry." There was a silence that followed, and in it, Derek had covered the shield back up and had leaned heavily against the window. "This doesn't mean anything," Stiles said, needing to fill silence like he hadn't in years.

"Doesn't it?" Derek asked, though there was a vaguely resigned look to him.

"Doesn't have to."

"What?" Derek asked, watching him fidgit.

"It doesn't have to. You've known for a while; I've known for a while. We can keep on like we are." It was an option, but the, his wolf had been scratching at the back of his mind for the last month, urging him toward something.

"I came here looking for it," Derek said finally. "If I wanted to keep ignoring it, I would have kept ignoring it."

"Thank God," Stiles said on an exhale, and Derek tossed his head back and laughed for the first time in months.

-Shield and Strength-

Derek had always liked his shield. It didn't matter who's it was or what it meant, because to him it was someone willing to sacrifice for him. For a long while, he didn't think he deserved it. For even longer after he figured out who it belonged to, he thought he didn't deserve the person that would stand there, between him and everythying.

Except, as he learned to grow as a person, as he became an adult and not just a scared child that had grown into a larger body, he learned that his soulmate wasn't looking for someone to stand behind. He wasn't Page, who was afraid of the world and needed someone to bolster her. He wasn't Kate, who wanted a shield of her own.

In the end, he was Stiles, who really just wanted someone to stand beside him, not above him or below him, in front of him or behind him. He just wanted someone to be there, with him, as he made his way through the world, and Derek? Well, Derek didn't want someone to stand in front of him, to act as a shield. He didn't want anyone to take a blow for him. He wanted someone willing to.

So the pair of them? Well, they worked a lot better than Derek ever thought they might.