Warning: Misgendering.

Delphinus Pollux Black was born on the twenty-third of June in the year nineteen sixty-two, son to Walburga and Orion Black and younger brother to Sirius and Regulus Black. The third son in the Noble and Most Ancient House of Black, the third heir to the male line in case anything were to happen to his two older brothers. There were two problems with this. One: Delphinus Pollux Black was not supposed to exist; and two:

Delphinus was a girl.

-o-

From the very start, she had known she was not a boy. Every time her parents referred to her as their son, every time her brothers referred to her as a younger brother, every time the word 'boy' spilled out of someone's lips, something in her would hiss in poisonous indignation.

"Not a boy," a voice would spit out. "Not a boy nor a man. Never male."

There were times when she thought of simply telling her family about it, but those thoughts were often followed by a crippling sense of horror and fear, the pounding of a frenzied heart in her ears and the knowledge, the surety that her family would… they would…

Delphinus tried not to think about what they would do.

In this cold and distant family, where fathers talked to their children in stilted tones and mothers only acknowledged children's presence when there was something they wanted from them, it didn't take a genius to know how they would react.

-o-

Delphinus grew up amongst talking portraits and house elves and wands. It was all she ever knew.

And yet.

She remembered large metallic carriages called cars, she remembered small rectangular devices called phones, she remembered large buildings that reached to the sky, aptly named skyscrapers, she remembered, she remembered, she remembered.

She remembered fragments of memory from a world she never knew. A life she never lived.

(Or at least, a life she never knew she lived.)

-o-

And then, when she was nine years old, an owl flies into the house carrying a letter in its beak. She could barely make out the words 'To Sirius Orion Black' in a neat cursive font before the letter was snatched up by her older brother. He tore it open eagerly, the crisp envelope turning into strips and shreds of paper that Delphinus eyed wistfully. The envelope had looked fancy and it had been such a shame for Sirius to destroy it like that.

"Delphi! Reggie!" Sirius exclaimed, immediately snapping Delphinus' attention to him. "I'm going to Hogwarts!"

"Of course you're going to Hogwarts," Regulus said dryly. "You've proven yourself capable of magic and, not to mention, you're a Black. Why wouldn't you go to Hogwarts? The letter is just formality at this point."

"Stop being such a party pooper!" Sirius stuck out his tongue playfully. "At least Delphi knows how to appreciate the letter, right? Delphi?"

Delphinus stared at the letter in Sirius' hands, his voice echoing in her head. 'I'm going to Hogwarts,' he had said. Hogwarts.

The word repeated itself over and over again. Hogwarts, Hogwarts, Hogwarts.

Harry. Potter.

"Oh," she said faintly.

"Delphi?" Regulus' voice held a hint of panic. "You're bleeding."

At his words, Delphinus became aware of a warm and sticky liquid dripping from her nose. She wiped it away, not at all surprised to see blood. She felt strangely detached from the situation, as if she were someplace very far away and she was watching everything through a screen. Her body suddenly felt foreign; the blood nor the hand in her line of vision did not seem to belong to her.

Harry Potter, the boy-who-lived-under-the-stairs. Harry Potter, the future savior of the wizarding world. Harry Potter, one of the bestselling book series in the world.

Harry Potter, the book series she had not read yet.

"Delphi!" Sirius' hands were now on her shoulder, shaking her back and forth. "Are you alright?"

"He won't be if you keep doing that!" Regulus quickly pushed himself between Sirius and Delphinus. "What he needs now is… uh…" Regulus floundered for a moment. "A healing spell!"

"Do you know a healing spell?" Sirius asked Regulus. Regulus shook his head.

"I was going to ask you that."

"Shit, damn."

"I think, I think either mother or father should know healing spells," Regulus brought the idea up reluctantly, already knowing that Sirius would shoot down the suggestion as soon as it was in the air.

"No way in hell," Sirius said flatly, living up to expectations. Walburga and Orion Black were not good parents, and their children's distrust and mutual dislike of their parents had forged a sort of camaraderie among the three of them.

If they didn't take care of each other, who would?

"Then… Kreacher?"

Sirius made a face. He wasn't very fond of the house elf – Kreacher reminded Sirius too much of Walburga Black for any sort of fondness to develop there – but he was willing to put aside his dislike for Delphinus. "Sure I guess," he agreed somewhat grudgingly.

"There's no need," came Delphinus' voice. "I'll be fine."

"But you're still bleeding!" Sirius said.

"I'll be fine," Delphinus repeated, exasperation coloring her tone. "It's just a nosebleed. I know how to deal with it."

"Are you sure?" Regulus asked, eying Delphinus closely to see if she was lying. She nodded her head and Regulus decided to let it go.

With ease, Delphinus pinched a spot near the bridge of her nose and tilted her head forwards to prevent choking on the blood. She didn't question herself as to why she knew how to treat a nosebleed, for she already knew the answer. It seemed impossible but no other theory made as much sense as this one did.

Delphinus Pollux Black had been reincarnated.

-o-

After the world-changing realization she had gone through, Delphinus couldn't help but be terrified. She might have not read the books but there were just some things that were common knowledge. Harry Potter, savior of the wizarding world, lived under the stairs. Dumbledore was the headmaster of Hogwarts. Voldemort was BAD, with a capital B-A-D. Sirius was going to get framed and imprisoned. War was coming.

Or, Delphinus thought numbly during dinner that day, hearing the idle conversation her parents were having about a 'Dark Lord'. War has already begun.

She tried her best not to listen, but it was difficult not to pay attention when she was already aware of the slur 'mudblood' spoken out loud as if it were nothing, the poisonous glee laced in their words when they talked about 'muggle-hunting', the respect in their voice when they mentioned the rising 'Dark Lord'.

Delphinus stared down at her food, bile rising in her throat.

War.

In her previous life, she had lived in peaceful times. She couldn't even begin to imagine the horrors of war, much less going through them. She tried to think about either of her brothers dying young and her heart clenched painfully, her brain rebelling at the very idea of it.

But war was war and, in her past life, Delphinus had never heard of Sirius Black having a younger brother before. That meant that Regulus… Regulus was dead by the time Harry Potter took his first breath. The question was if he had been on the side of justice or if he had been on the side of. Lord Voldemort.

Delphinus did not want to know.

-o-

Delphinus never understood why her family always had to dress so stuffily whenever they left the house. Well, she understood that her parents wanted to make the statement of "I am better than you" loud and clear to everyone around the, but it was rather uncomfortable to wear such restricting black clothing wherever they went.

Funeral attire really seemed out of place in Diagon Alley.

The people around them gave them a wide berth as they walked down the streets and towards Ollivanders. Since Sirius was going to Hogwarts, it was time to get him a wand.

Contrary to popular belief, the Blacks did not give their children wands the moment they were able to grasp things in their little hands and then teach them dark spells right off the bat. The Most Noble and Ancient House of Black would wait until their child was accepted into Hogwarts before purchasing a wand for them, seeing it as a symbolic rite of passage.

Delphinus noted that Regulus seemed a little jealous that Sirius would be getting his wand first, but he remained quiet about it. There was no doubt that he would ask Sirius to lend him the wand once they were home and out of sight from their parents. Delphinus, on the other hand, just wanted to enter the bookstore as soon as possible. The last time she had set foot in Flourish and Blotts had been an agonizing three months ago, and there definitely had to be new books in stock by now. But first, Sirius' wand.

Ollivander had made Sirius sit through a series of bizarre measurements which Sirius took in stride, even grinning at Regulus and Delphinus when his parents weren't looking.

The first few wands Sirius tried did not work out for him – one even made three boxes spontaneously combust in a row – until Ollivander gave him a nice, straight wand with a pretty dark coloring. Sirius gave it a swish and beautiful sparks of gold and red erupted from the tip.

"Cypress and dragon heartstring," Ollivander said with an air of finality. "I am always honored to meet a wielder of a cypress wand. You are meant for great and heroic things." He said the last bit with a hint of sadness and Delphinus could not help but feel her chest tighten at his words. Being heroic was one thing, but being heroic in times of war and turmoil was…

Delphinus forcibly pushed those thoughts away, focusing on being happy for Sirius. So what if Sirius was meant for heroic things? He had Regulus and Dephinus to be by his side, watching his back and covering his weak spots. Nothing would happen to him, not if the three of them stuck together.

Sirius, Regulus, and Delphinus. Siri, Reggie, and Delphi. They would stick together through thick and thin, in sickness and in health, forever and ever, because they were siblings. Because it was them versus the world.

Because, if they can't rely on each other, who else could they rely on?

-o-

The fact that Sirius was going to be gone for nearly an entire year didn't quite hit Delphinus until they were at King Cross Station.

It was there, standing by the tracks beside the metallic red of the Hogwarts Express, that it hit her. Sirius was leaving. Sirius was leaving.

What if he didn't come back?

She didn't notice she had been hyperventilating until cold hands touched her cheeks and a pair of familiar grey eyes entered her line of vision. The sight of Regulus with his knees partially bent in a half squat was funny enough to reach Delphinus and she giggled, making Regulus smile.

"What's wrong, Delphi?" he asked. Delphinus hesitated for a moment.

"I'm scared that… Siri, he, won't. He won't come— What if Siri gets hurt in Hogwarts? What if he doesn't come back home?"

"Hmm…" One thing Delphinus loved about Regulus was that he always treated her worries seriously and never dismissed them. She remembered that there was one time she was five and she had been worried that there was a lethifold under the bed. Sirius had simply laughed at her and told her that lethifolds did not exist in England. Regulus, on the other hand, stayed with her in her bed and pulled an all-nighter so that she could sleep peacefully. This continued for two days until Sirius made Kreacher look under the bed for them to check for lethifolds.

(The lethifold in question was merely born from the idle imagination of a young child who had read too many magical creature encyclopedias before bed, and two black robes that had been missing for three weeks.)

"Why not we ask Sirius to write a letter to us every week?" Regulus suggested. Delphinus nodded slowly. It would be nice to get an update from Sirius frequently and in regular intervals so that they would know if Sirius ran into any trouble in Hogwarts although, knowing Regulus, he probably wanted to scope out the general atmosphere in Hogwarts before attending it. It would be useful to be updated on the Slytherin social hierarchy as well, because surely Sirius would be going to Slytherin, right? He was a Black, after all. Everyone knew that all Blacks went to Slytherin.

"What are you guys talking about?" Sirius forcibly inserted himself into the conversation. It seemed that Walburga and Orion had finished giving Sirius the 'Uphold The Family Name' speech and were now socializing with their fellow pureblood parents.

"Oh, we were just talking about coercing you to write to us every week," Regulus said nonchalantly.

"Oh, I see. Wait, coerce?" Sirius yelped. "And every week? That's too much! Why not once a month or something?" he whined.

"But Siri," Delphi looked up at her brother with wide eyes. "We just want to know how you're doing! You don't even need to write a lot. We're just worried about you."

"Delphi, you, Reggie, ugh, stop—" Sirius threw his hands up in the air. "Fine, I'll write every week. Just stop looking at me like that!"

"Yay!" Forgoing all thoughts of Black nobility and manners, Delphinus flung herself at Sirius for a hug. "Thank you Siri!"

"Psshhh, it's no problem," Sirius' cheeks were red, not used to such open displays of affection. He gave Regulus a Look, asking for help, but Regulus seemed happy to watch Delphinus hug Sirius in broad daylight.

"Delphinus," a cold voice said from behind Sirius that made all three siblings freeze up. The previously warm atmosphere plunged into icy coldness at that one word and Delphi immediately let go of Sirius, taking a few steps back and putting ample space in between her and her brother.

Orion Black stood behind Sirius, eyes piecing as he looked down at Delphinus and Delphinus suddenly felt very, very small.

"I apologise, father," she said quietly. "I will not do that again."

"See to it that you won't," was Orion's only answer before he turned to Sirius. "It is time to leave. Remember, you must do your best to uphold the Black's family name. It wouldn't do for lesser people to look down on us."

"Yes father," Sirius said flippantly. Orion didn't seem to notice.

"I'll be leaving then," Sirius said to his siblings. "Expect the first letter in exactly six days."

"See you, Siri—us," Delphinus quickly caught her mistake and fixed it before she once again caught the attention of her father. "Be safe."

"Goodbye Sirius," Regulus said evenly with a small nod, the perfect picture of a pureblood heir.

Sirius nodded back and then slowly made his way towards the Hogwarts express, glancing back over his shoulder every now and then to make eye contact with his siblings. Right before he boarded the train, he looked back one last time to wave, and then he was gone.

-o-

The rest of the day went by smoothly and Orion seemed to have forgotten about Delphinus' public display of affection. That was good. In Delphinus' opinion, any attention from her parents was bad attention.

Delphinus and Regulus spent the rest of the day reading about magical herbs and potions, preparing themselves for a long six-day wait for Sirius' letter when an owl flew into house, addressed to Walburga Black. Delphinus and Regulus paid to attention to it at first, not until Walburga gasped and started to shriek. Delphinus winced and Regulus unconsciously put his tense body in between his mother and his sibling, eyes wide with fear but still trained on Walburga in an attempt to find out what had set her off this time.

"Walburga?" Orion Black quickly entered the room. "What's wrong?"

"What's wrong? What's wrong?" she screeched, throwing the letter in her hands at Orion. "This is what's wrong!"

Orion scanned the letter and his expression closed off.

"Gryffindor," he said with no emotion.

It was with that word that everything fell apart.

Author's notes

the title is a placeholder. it's late.

I found an old sioc story i wrote like around five plus years ago and i decided to rewrite it entirely. can you believe that delphinus used to be able to see people's magical auras? what in the world is that? well, it's pretty cool but only in the hands of a good author.

delphinus is trans female. i'm here being upfront with you: delphinus is assigned male at birth, and she is female. a girl. she/her pronouns, even if other people in the story might refer to her otherwise. there's a lot of misgendering in this fic because delphinus is still in the closet when it comes to her family.

this story is also going to be very oc-centric and it is my self-indulgent piece of fiction. i just want to have fun, and i'm uploading this for myself. this is literally oc hell there's going to be so many because i have 0 clue who are all the people in the marauders era and like hell i'm sorting delphinus into gryffindor.

if anyone reads this fic, thank you. i hope that you will enjoy it, even if it's only a little.