Understanding and Agreement
Sin Regulus could remember he looked up to his brother because Sirius was one those people that even if they were either 4 or 20 they always drawn people to them. Either by his charm, smile, wit, decision or stubbornness; everything that meant being Sirius was admirable.
Many compared the brothers saying that they looked like twins, even if they born a year apart, however Regulus knew that wasn't the case. Sirius always walked tall, with pride; like the world belonged to him. Regulus had the same stance typical of the Black family, but he never knew how to bare it like Sirius, for his brother it was natural.
Sirius was also out going, knew how to get along with people, and was always the center of attention. Regulus was always withdrawn, he spoke only when spoken to and; even if he never rejected interaction; he was kind of a loner in comparison to his older brother.
Sometimes Regulus envied how easy it was for his older brother to retain and comprehend even the more complicated themes that were expose to the Black brothers, was it magic, politics, chess plays, Sirius seemed to have been born with the knowledge; whereas Regulus always seem to take longer to assimilate everything before him.
Most of the time he assumed that those things didn't mater, Sirius was the favorite, the heir of the Black name; so Regulus could "relax", be the best version of him that he could be, and still please his parents.
But even with the love and admiration, there was something Regulus couldn't do for his brother; understand him. No matter the age, Regulus never understood Sirius.
When he was 4 he couldn't wrap his mind around the stilted excursion to the kitchen, sneaking form Kreacher or his parents, just to reach the cookies on the top shelf. That only meant they would get scold and none of them wanted that. At 6 he thought it was impossible to comprehend why Sirius pulled Bellatrix hair every time she mentioned Hogwarts; after the scolding from their aunt and uncle his father would surely would take "drastic" measures to make Sirius comprehend he shouldn't behave like that. In his 10's he certainly didn't understood why Sirius would like to go out of the house without supervision, Regulus didn't comprehend why Sirius was so determined to know the Muggles that live around them, if their parents caught him the punishment would be far from orthodox.
"Aren't you curious, Reg?" Sirius said to him one afternoon, "Wont you want to know why are they so different? Would they look like Kreacher? Maybe they are like the Squibs?"
Regulus shook his head and tried to convince him to stay home, and don't defy their parents, however Sirius' charm and charisma won the battle. That afternoon he discovered that the Muggles were Squibs without imagination; without the possibility of making a simple potion and he didn't saw the appeal of being involver with them.
Eventually Sirius made it to Hogwarts, and that's when things when down hill. Sirius, with the influence of the Potter cousin, ended up in Gryffindor, for the dislike of their parents. Countless of Black generations kept the tradition of being in Slytherin tainted by Sirius behavior. By Christmas his brother made it home with a little regret, it wasn't like he wanted to challenge his parents; it was more like he didn't mind the change of plans. Sirius would the Black name shine no matter the House he was in.
That December the tales of the castle excited Regulus. Sirius talked about his Housemates, the professors, and every place he wanted to explore. By the summer something changed in his brother, his rebellious vein grew, however the distance between both brothers wasn't so large. When Regulus arrived at Hogwarts things seem a little different than at home; Sirius always kept his aura, but he had encounters with every cousin and acquaintance.
Even if the relationship with his brother was a little distant, because of the different Houses, Sirius always made time to talk to Reg; between classes, after lessons, o on the weekends; eventually he got a two-way-mirror and things seem to get back to normal between them. But even so, Regulus still didn't understood Sirius.
Things got tense by the minute, Sirius question everything he was told and their parents didn't tolerate that kind of behavior in number 12; much less express them out loud. So the older of the Black children lost his natural way of walk around the house, much like his good mood disappear being stuck on those walls.
When he reached 14 Regulus spoke less and less with his brother, his parents took away their hope on Sirius; even if they still tried to change his behavior according to their standards; and change their attention to the son they consider best fit to be the heir of the name.
Walburga kept allowing some liberties to Sirius with her aunt Dorea, however the "drastic measures" became "costumes" and the unimaginable became routine. Sirius would wake up in a bad mood, Walburga would yell, Orion would take him to the library, Regulus would see a new red scar in the face of his brother, and that would repeat at least once a week.
Regulus tried to talk to Sirius, the anger and sadness was so rare in the face of his brother that it broke the heart youngest of the Black.
"Why do you have to keep opposing our parents?" he asked without reproach and fill with concern.
"I don't do it because I'm stubborn, Reg," the oldest of the Black sons answered with a sad smile on his face, "but you never doubted what they taught us."
"I never had a reason to."
"No?" he asked and got a shake of the head for an answer, "Do you really think that Muggleborns are inferior to us? That they deserve to be treated different because of the way they were brought up? Or even for thinking different?"
Regulus thought his answer four a couple of minutes.
"They are different from us, Sirius."
"Yeah, but they don't deserve to be treated better or worst because of their parents. I things were backwards, would you like to be treated different?"
"But things aren't different." Regulus didn't understand what good it made to ponder on those kind of things, that's why he receive the end of a bitter smile.
That week Sirius left home; covered with blood, bruises, and cuts. Leaving Walburga disconsolate, Orion perplex, and Regulus taking his place.
Eventually Regulus filled the void that his brother left, his parents never talked about their first born, and a new black spot garnish the tapestry of the Black's Family Tree. Regulus started to feel awkward in the middle of an uncomfortable situation, his feelings for his brother didn't change; he still admire him, love him, and not understanding him; but it was better for everyone if he didn't kept in touch.
With time the tow-way-mirror stop vibrating, and Regulus Housemates talked about a new regime that would completely change the Wizarding World with the same ideas his parents shared. That made Sirius broke his silence trying to dissuade him from joining the Knights of Walpurgis; however the words of his brother didn't made sense, joining a club of purebloods to please his parents shouldn't worry him that much.
When he got the tattoo on his left arm he remember that night and the worry of his brother. At first he went to the reunion for his parents, but his brother's doubts crept to his subconscious, and now he wasn't sure himself that keeping to ideals were the best for him.
For a long time he tried to burry his doubts with excuses, and remorse with logic, but at his 18 years, after three years of service, Regulus knew that being a Death Eater wasn't what he wanted.
He discover this by looking at a pair of piercing, wide open, blue eyes; that looked at him with wonder, fear and plead.
Marlene McKinnon was kneeled in the center of a Death Eater circle, trying to free herself form the magic bounds; with a torn rope and blood gushing out of some cut on her skin. She looked around with those piercing blue eyes, undressing Regulus from his mask and looking directly into his soul.
Marlene McKinnon, the nice girl that came to drink tea with his mother every summer afternoon. McKinnon, his first crush; which Sirius made fun of and she answered with a warm smile. Sweet Marlene, that was always caring and kind with everyone, was in the middle of a circle in front of the dark Lord and Regulus knew she wouldn't come out of it.
Why her? Marlene was a pureblood. Why her? Marlene was an example of a great woman. Why her?Because she thinks different, Sirius's voice resounded in his head just before the scene was wrapped on a green light.
Regulus never understood Sirius, but when he saw the death body of the blond he comprehend perfectly the way his brother reasoned.