Lives change like the weather
It was the 1st of July, 1976. Regulus's fourth school year had ended only about a week ago and Sirius had run away from home merely a few days later. Just a few hours ago, Regulus had woken up with the sudden knowledge that he could change things for the better and had been thinking about just how to do that ever since. He knew what he had to prevent, but he didn't know how to get there.
First of all, he needed to stop the war before it could start in the first place. In order to do that, he had to get rid of all of the potential death eaters as well as find all of the Horcruxes Voldemort had already created and destroying them. But how was he supposed to do that? He knew he couldn't do it on his own, despite how talented and knowledgeable he was, but he feared that whoever he asked would either not believe him or would believe him, but would not be able to help him. Honestly, he blamed the wizarding school system, specifically the one of wizarding Britain. He himself wasn't affected because he liked to educate himself in his own time, but whenever he coincidentally noted just how clueless the other students were, he could only shake his head. Perhaps he had to start with that, a better education for the wizarding world so the next time a dark lord was trying to establish himself it wouldn't even get this far.
He kept that idea in the back of his head. If he put his mind to it, he could probably come up with a whole new and functioning school system before the school year started again two months later, but first, he had to get rid of more pressing problems, such as his parents who could legally prevent him from doing so as well as Dumbledore, the manipulative fool who honestly thought Regulus had no idea about his past with Gellert Grindelwald and how he blatantly prioritized the well-being of the Gryffindors while simultaneously not caring about the Slytherins at all.
He already had an idea for getting rid of him, but getting rid of his parents took priority. He didn't want to outright kill them, no, he still had morals, but there had to be something he could do... He thought about it for hours, even while eating dinner with said parents. They of course didn't notice anything, they had been brooding silently ever since Sirius had run away. He was about to excuse himself and go back to his room for the night, but his mother asked him to stay back and play the piano for her. She hadn't asked him to in a while, but he knew that his music was something she genuinely enjoyed so he agreed and entertained his parents.
And that's when he suddenly remembered his dream from last night. More specifically, the youth in his dream who he had identified as Lord Apollo, known as the God of the arts, archery, healing and prophecy, but also the God of plagues and diseases. His Lord had helped him once, perhaps he would be willing to help him again? So while playing absentmindedly, he started praying to his Lord, praising His name, thanking Him for His enlightenment.
Then he hesitantly went on to ask Him for help again.
It was the 2nd of July, 1976. Sirius had finally escaped his family a few days ago and was now permanently staying at the Potters' house. He was happy there, he really was! Euphemia Potter was an amazing woman who gave all of her love freely and never asked for anything in return. Fleamont Potter had a naturally calming presence that reminded him of a fire's warmth in a cold winter's night. And James Potter had been his best friend for years, they were as close as brothers. But no matter how much he liked them, they were not his little brother. Though they had been very distant in recent years, Sirius still loved Regulus fiercely and if his little brother gave any indication that he wanted out, that he did not agree with their parents, Sirius would be the happiest boy in the whole world and would readily reconcile with his beloved little brother.
Sirius was outside with James, the two of them spending time together in the Potters' garden because it was summer after all. They were interrupted by James's parents who hurriedly called them inside.
"What's going on?" James asked as soon as they were inside.
His parents hesitantly looked at each other and then at Sirius before reluctantly handing over the newest edition of the Daily Prophet. As soon as Sirius saw the headline he had to sit down to read through the article quietly.
REGULUS ARCTURUS BLACK BECOMES LORD BLACK
WIZARDING LONDON - The Noble and Most Ancient House of Black is known to most of us for being one of the oldest Wizarding families around as well as their involvement with the Dark Arts, most notably Bellatrix Lestrange (née Black) and the ex-matriarch Walburga Black herself. You read that right, ex-matriarch. Yesterday at approximately 11:28 PM, Regulus Black had reportedly called at St. Mungo's and told them that he had found his parents in the living room with strange blisters all over their arms. He had immediately put a salve on the blisters and hadn't thought more about it, until his mother started screaming at him for no apparent reason, followed by tearfully apologizing and then hysterically screaming. His father is said to have displayed similar behavior. At that point he wanted to call St. Mungo's but was stopped by another strange occurrence, namely both of his parents starting to lose large patches of hair out of nowhere. While trying to help them to their bedroom to have them rest, they claimed that their ankles had started to hurt and neither of them could manage to walk more than a few steps. Worried, because he was not familiar with these symptoms, he hurriedly called healers and when they arrived the blisters had spread everywhere and they had lost most of their hair. And although the healers tried their best, they reportedly died at around 2 o'clock in the morning.
Though these are certainly very strange circumstances, and we share our condolences with the whole family, this has even bigger implications for one Regulus Black. This had not been public knowledge yet, but his older brother and former heir Sirius Orion Black had run away from home only a few days prior, which means that Regulus Black had been named heir by his parents and is now the acting Lord Black and that at only 14! His first act as Lord Black was declaring that the family would hold a small ceremony for his parents with more information to follow.
Sirius had to read through the article four times before all of the information finally caught up to him.
"Dead?" he asked in a shocked voice.
"Who's dead?" James sounded just as confused as Sirius felt.
"My parents, apparently."
"Wait what?"
Sirius had no idea what was going on. The situation seemed completely surreal to him. Just a few days ago, his mother had screamed at him and threatened to crucio him until he fled from Grimmauld Place, all while his father simply looked on while ignoring the problem at hand. And now they were dead? How could that have happened? And that wasn't even the strangest thing. Apparently, his little brother was Lord Black now! He was, what, 14? 15 in a few months? Sirius was more than just scared for his little brother. Sure, Sirius knew that Regulus could take care of himself, he was an incredibly talented wizard after all, but he was still just a child his eyes. And he himself had been disowned, so it's not like he could take his brother's burden either, not even if he had wanted to.
"I, I need to talk to Regulus." he decided promptly and was about to apparate away without a second thought until he was stopped by the Potters.
"Sirius, I understand, but don't act rashly now. Think before you act. Regulus is now the acting Lord Black and probably has a lot going on with your parents' funeral and all of the official business that comes with taking over a house like the House of Black. Give him some time. He'll come around when he needs you and if not, you can always go and see how he's doing in a few days or weeks." Euphemia assured him and he reluctantly agreed.
He just hoped that someone could help his little brother figure everything out.
Unbeknownst to him, Regulus had everything completely figured out. One obstacle out of the way, he had to take care of the Hogwarts situation. No one would be of any use to his secret mission when nobody had the necessary knowledge to be an asset to the wizarding world.
He had not been lying when he said his parents' funeral would be a quiet affair, he just left out the part of having to deal with some other business. His true first act as Lord Black was the recruitment of people he trusted for a secret organization. Their purpose? Finding death eaters and reporting them, finding and destroying the Horcruxes and surprisingly the most important order of business, the creation of a new Hogwarts.
In his head, he dubbed the organization the Krystallon and he already had some future members in mind, starting with his beloved older brother and his friends.