A/N: Had this idea while working on my X-Men/HP, having watched both Days of Future Past and Age of Ultron recently. References Marvel's X-Men in the form of mutants, though takes place in the MCU; if you don't know what mutants are then you can't call yourself a Marvel fan.

Wanda always knew she had a brother.

Whenever she would ask her parents would always frown, shake their heads, and tell her not to ask. No matter how hard she tried they would always say the same thing: You don't have a brother.

She didn't believe them. He haunted her thoughts, a boy with her dark hair and smile, one who would play with her and tease her and understand her better than anyone else in the world. Every night she'd think of him when she went to sleep, and every morning she'd look for him only to remember he wasn't there.

Sometimes at school Wanda would turn to share a joke with him only to meet with a vacant chair, or would offer part of her food to empty space. Her teachers and classmates thought he was her imaginary friend, some playing along and some laughing at her. When she drew pictures of her family they always included him, the brother-that-never-was, and as she grew older she could see their amusement turn to concern, and then to annoyance. Daydreamer, the nice ones called her; liar said the ones who weren't.

Wanda's parents worried for her. They brought her to doctors, to therapists, all of whom would try to pick her apart and understand, but she never let doubt trickle in. They were liars, all of them, trying to make her forget the most important person in her life. Even without a name or a face he still managed to hold a place in her heart.

Occasionally she'd see him in her dreams, clear as crystal; messy dark brown hair, bright green eyes like her mother's, wearing baggy clothes and sleeping in a tiny room. He never saw her but she always loved those dreams, loved imagining what he'd be like. He was nice, she knew; he would whisper to the spiders that lived in the room like they were people and draw pictures just like she did. And no matter how mean the voices outside were to him, he was never angry. And even if the details faded when she woke up, even if she forgot all but those bright eyes, they never failed to make her smile.

Wanda clung to those dreams like lifelines, telling herself that one day, when she was big, she'd go find him and take him home. Make the voices go away and hug him tighter than anyone else ever could, never let him go. That dream was everything to her, a promise she made herself.

And then her parents died in an explosion and she was left all alone, and for the first time that promise was forgotten in place of another, a burning hatred which festered for all things American, for their weapons of destruction, and for Tony Stark.

When Wanda met Baron Strucker, she knew instantly that he was not a man to be trusted. The senses she had trusted all her life told her that this man was a liar by nature, the kind of man who would toss aside his own young for the slightest chance to fulfill his desires. And yet when he spoke she knew it was the truth, that he lacked the respect for her to lie when he told her that his methods could end in her death.

"We will reach inside you," he told her, his eyes cold, "to find any power locked within. And either it will ignite and grant you abilities beyond your wildest dreams, or your body will crumble away and die."

There was no hesitation in Wanda's voice when she accepted. The others screamed and burned but not her; they brought her to the brink of death but it was her own strength that pulled her back, and with her came power like she'd never seen. The power to change the world.

"Hail HYDRA," she breathed, taking the hand of the now-smiling Baron Strucker. Her loyalty was sworn in pain and blood and she knew that this was the only way to protect others like her, those who had been victims of the negligence of the privileged. Wanda would be their champion.

"We will destroy the Avengers," Strucker said, deep voice strangely alight with glee. "We will crush SHIELD and take the world as our own. And then there will be no more suffering, no more pain, no more death. Just perfect order."

It became a mantra, another promise to herself through the long days of training and the long nights of experiments. No more suffering. No more pain. No more death. They trained her to kill, and then worse; to reach into a man's thoughts and turn his mind against him, make him wither and crumble until he was but a broken shell with no identity but that which she gave him.

But all that was forgotten the day she discovered magic.

They started sending her on missions to train her, using her as proverbial muscle to display the power of HYDRA. Her abilities drew not just fear, but admiration, and that was exactly what Baron Strucker wanted; people signing up to be experimented on, not just dragged in by force. In a world of superheroes and mutants the appeal of gaining such power drew them like moths to the flame.

One such mission took her into Ukraine to hunt down several of old HYDRA's loyalists who failed to follow Baron Strucker. A base right in the heart of their capital, the members had been funding terrorist attacks against foreign nations using stolen American technology.

Their end came swiftly, on bolts of scarlet energy and weapons of death. And though it made her skin crawl and her stomach tense, Wanda told herself that it was the right thing to do, that these men deserved it. Whether or not she believed it was something she told no one.

Inside the base they found prisoners, men and women of either political or scientific value. It only took a flick of her fingers for the locks to disengage and set them free. Fearful glances shot her way as they ran, released to spread the warning to the other traitors. All but one.

The man looked to be about thirty, his blond hair matted and greasy. But when he saw her power rip the door off its hinges there was just awe in his gaze, not the uncertainty that had graced the others. "Come with me," she told him, beckoning.

His eyes never left her as she escorted him from the building, blasting aside anyone who came near. "I've never seen anyone with magic like yours," he told her as they emerged into the sunlight, his eyes closing for a moment as he reveled in the feeling. "Did the Ministry send you?"

Wanda brushed aside his question of magic, dismissing the notion as foolish off-hand. "I am not from any Ministry," she told him as she tried to leave him, only for his hand to grab her arm.

"You're Sokovian," the man noted, eyes widening as he looked her over. "But I thought the government deemed it illegal for wizards to live there?"

She paused at his words, letting a trickle of energy into his mind to scan for lies. What she found was something far more shocking. "Wizards?"

His eyes widened and he jerked back suddenly. "I—I'm sorry," he stuttered, backing away. "I thought you were—" Her power froze him in his tracks and his eyes grew wide.

Wanda reached into his mind once again, compelling him to spill the information that seemed to ignite some ancient knowledge in the back of her mind. The word 'wizards' felt like an ancient song she'd long forgotten, a memory older than herself.

"The government tried to kidnap magical children as weapons," the man was forced to say. "The International Confederation of Wizards decided that any muggleborn children would be removed upon the first occurrence of accidental magic to prevent use as weapons; they were having a hard enough time dealing with the mutants' immunity to our spells. Their families' memories were altered and the children were adopted by foreign families—"

Memories flickered to the forefront of his mind and she latched onto them, letting them play out in front of her like a movie.

Mothers and fathers screaming as their children were ripped from their arms—

Blank looks descending on their faces as a white light stripped away their love, their care, their memories—

Men and women in robes using power so like her own but so very different too, using wands and spells—

An entire society hidden away behind illusions and deceptions, a world of people wielding power like no one could imagine—

Wanda released him and he collapsed, gasping, curling into a shivering ball as her power receded. She did not notice, her mind too busy piecing together the secrets she'd torn from his mind, trying to understand why this meant so much to her. Like pieces of a puzzle the sparks of memory began to connect, flashing behind her eyes.

And then she remembered.

"Wanda! Wanda, look!"

Wanda looked up as her brother's voice rang out, high and excited as the boy himself. His dark hair whipped around in the wind as he plodded over to her, big eyes shining as he held out one hand, showing her the butterfly perched delicately on his forefinger. Though its midnight blue wings were beautiful, dotted with white like the night sky, a large portion of the right one had been ripped away, leaving it unable to fly.

She looked up at her twin's face, frowning. "It's hurt," the three-year old noted sadly, watching it valiantly flutter its damaged wings in an attempt to lift off, but to no avail.

Pietro frowned, brow furrowing in an adult-like look of concentration as he examined it. Green eyes narrowed and he bit his bottom lip, staring at the wing intently.

Wanda gasped as suddenly the ragged edges of the wing began to smooth, slowly but surely knitting themselves back together. The tear began to shrink as the wing healed itself, the empty portion slowly but surely refilling. And before she knew it the insect was flapping wings each as perfect as the other, lifting free of Pietro's hand and taking off into the sky.

The duo shared an amazed look as they followed the creature to the flowerbeds; oblivious to what had just transpired, too focused on watching the butterfly suck nectar from a tulip. For that moment everything was perfect.

But then the peace was broken when, with cracks like gunshots, several people in cloaks materialized on the front lawn. Both children screamed and clung to each other, their parents rushing from the house at the sound, only to find themselves at the end of the intruders' sticks. A white light emanated from the tips and suddenly their fear slid away, becoming an eerie blankness.

Wanda grabbed onto her brother's arms as they tried to run, only for another person to appear in front of them. Pietro was wrenched from her grasp with a cry and she screamed, grabbing for him, but then one of the sticks was held in her face and a single world spoken.

"Obliviate."

Snow fell in thick, fluffy flakes on the town of Godric's Hollow, stifling any sound with a blanket of quiet that bordered on eerie. The rustic cottages were dark, the occupants fast asleep. Christmas lights and wreaths dotted the doors and windowsills, giving tribute to the holiday Wanda had long since stopped celebrating.

Her feet crunched loudly as she walked through the snow, following her instincts like she had always done towards the old church in the distance. It was fortunate that there was no one out this late to see her, standing out in a long red coat, eyes glowing with power. She was following a tether; a pull that she knew was leading her to the one place she always knew she needed to go.

Strucker wouldn't be pleased at her disappearance, Wanda knew. Though she had paused long enough to send a message with one of the HYDRA grunts, he would likely send men after her, furious at losing his prize. It didn't matter; not in the face of this.

The tug led her around the side of the church to an old fence, behind which lay a cemetery. The stones were old, names long faded and covered in snow, forgotten. She paid them no mind as she slipped past like a ghost, her heartbeat pounding in her chest as she grew nearer and nearer to her goal.

Finally she saw a figure in the distance, and she stilled. Two of them she realized, but it was the one of the left that truly mattered. Her breath caught in her throat as the pair turned, eyes widening at the sight of her, their wands pulled from their pockets in a show of warning.

Wanda didn't care. She strode forward without an ounce of fear, ignoring the girl's warnings for her to stop. A blast of energy shot past her and she flicked a finger, yanking the weapon from the girl's hands and dropping it into the snow. The boy was still, eyes—green just like she imagined—fixed on her in the same way hers did on him.

She stopped right in front of him, their height difference meaning nothing as brown eyes met green. His own held no recognition, just confusion and perhaps a bit of worry, but she didn't care, finally putting a face to the name she'd carried for so long. One pale hand raised up, scarlet energy dancing from her forefinger, and when it made contact with his chest he gasped aloud.

"Pietro."

Harry used to dream of having a sister. Whenever the Dursleys gave him a hard time and locked him in his cupboard he'd wish really, really hard that he had a sister. Sometimes he'd image that she was standing there with him, or he'd dream of them playing together. Petunia had gotten angry when he'd asked, telling him that one freak was enough, but he always hoped she was wrong, that maybe he did have a sister out there.

When he'd discovered magic was real that had been one of the first things he'd asked Hagrid, if he had any family. But the half-giant had just chuckled and shaken his head, saying, "Now why'd ya think tha'?" Even Dumbledore had told him no after he'd found Harry looking into the Mirror of Erised.

That was the first time he'd really seen her and remembered her. She looked a lot like him; same dark hair, same facial features, the only real difference was their eyes. While his were emerald-green hers were sky-blue. The image in the Mirror had smiled and waved, holding his reflection's hand and if he looked at it long enough he could almost feel it in his own.

But then the Headmaster took away the Mirror and Harry never saw her again. However, he always remembered the way she'd looked, and no matter how hard it got sometimes, her face always came back to him. He'd used that memory to power his Patronus Charm, to overwhelm the Imperius, and to combat Voldemort's possession of him at the Ministry. She was his lifeline.

He never told Hermione and Ron about this. It was too secret, too personal; a burning desire they could never understand. Hermione would have smiled and told him it was sweet, but would have told him not to dwell on it. Ron would jokingly offer Ginny to him, missing the point entirely but making Harry feel better all the same.

As the war against Voldemort grew darker he thought of her less and less, something which felt horribly like betrayal. He would wonder if it was better this way, if he was better alone; if she was real then she'd have been yet another casualty in this fight, another innocent person dragged into his conflict like Ron and Hermione had been.

Sensing his ever-sinking mood Hermione had taken him to Godric's Hollow on Christmas Eve. It was quiet there, peaceful, away from the chaos of the magical world and even the turmoil of the human one. Both sides seemed to push against each other more and more each day; purebloods and magic on one side, mutants and superheroes on the other, and he knew one day that wall would shatter. But here, in Godric's Hollow, it was like time had stood still.

James and Lily's names were far from new, the edges of the words rounded over by the elements. The graveyard carried an aura of loneliness unlike anything he'd ever felt, of a hundred lives that had flickered and faded away before he'd even been conceived. So many stories lost to time, so many people who weren't even missed.

Staring at his parents gravesites he suddenly felt at peace with their deaths. They had loved him, died for him, and for the first time he understood what that sacrifice must have meant. He would gladly die for his friends if it would save them; how much James and Lily must've cared to die for him with no hesitation.

The snow fell lightly on them, muffling any sound with a thick blanket of white. The cold made Hermione shiver but to him it felt nice, cleansing almost. It was like the snow wiped away all traces of the old, paving the way for something brand new; what it was he had no idea.

Soft crunches sounded from behind him but he ignored it at first, even as Hermione stiffened and turned. It was only when he felt something hot and sharp trail over his skin—like a surge of exhilaration—that he turned to see their visitor.

She was dressed all in red, her skin pale and eyes dark. Brown hair fell in waves over her shoulders, her boots making loud thuds as they pierced the snow. Hermione raised her wand in warning but Harry could only stand there, familiarity roaring to life inside him like a wildfire. Even as the muggleborn's wand was wrenched from her hand he didn't move, not until the girl's hand was placed against his chest and he finally saw the sky-blue eyes looking up at him.

A burst of red light danced across her skin as something sparked to life, a memory that had been buried long, long ago, of a little boy and girl and a badly damaged butterfly. And as she breathed a name in greeting, he remembered the one that had been just out of his reach as long as he could remember.

"Wanda."

A/N: I plan to add another chapter or two later on, likely branching into Age of Ultron. Don't know when it'll be though.

Also, any X-Men fans try taking a look at my X-Men/HP story, From Fire. Unlike a great many of those, it does NOT feature any kind of overpowered wandless mutant/wizard Harry, though it might not seem that way at first glance. Just wait; I guarantee you won't see the reason for his powers coming. At the moment I have 60,000 words written so I can promise it won't be abandoned anytime soon.