Good things never last
As a young girl, Bella used to love her aunt Walburga for she seemed to be the only woman in her family not to be placid in her following of the expectations of women in their society. She would sit outside the doors every time her aunt would argue with someone, relishing in the sound of her voice getting louder and louder, the defiance more prominent with each new octave her voice reached. She would admire the fact that she had never allowed her identity to be erased, after marriage she was still a Black, if she had married her cousin to stay that way, it was too young Bella, was just a symbol of her strength and her steadfast loyalty to herself, her family and to the fight of not allowing oneself to be one of the thousands of victims this society had created. Walburga although married to the head of the house, Black never allowed her voice to be diminished and never allowed herself to be swept into a corner and forgotten. So even if the young girl had listened to countless tirades of everyone in her family complaining about her aunt, she was even more impressed by this woman who even with the complaints of others still got what she wanted.
But as Bellatrix grew older and her aunt's voice grew shriller she understood that Walburga was just like the rest of them, the system had conquered her, she had been weak, and she had allowed herself to be sold off like a broodmare to a husband that respected her just because she was a Black not because she was a phenomenal witch or as an inspiring individual but simply because of duty. She understood that the screams were her aunt's way to wallow about the fate she had allowed for herself. The screams were in Bellatrix's eyes no longer a sign of defiance or strength but just a woman who couldn't accept the choice she had made, and so what had once been love had been poisoned and slowly but surely blossomed into dislike. Walburga had been weak and was still weak when she refused to push Bellatrix toward the dreams that had once been hers before getting married. She had failed herself and a generation of Black girls after her. Bellatrix refused, she swore never to be the same.
The feeling of disgust that now came normally at the sight of her childhood idol grew tenfold when she brought Sirius Orion Black III into the world, not because of the child-it was the best thing she had ever done-but because of the way she treated the child. She saw him as a symbol of the head of the house that had pressured her into accepting this life, without seeing the magic that seemed to shimmer around the young child (later, when Sirius would be sorted into Gryffindor, she would blame his mother and would go as far as to curse her). Bellatrix knew the feeling of ignored talent way too intimately. So Bella, a girl considered the opposite of a good maternal figure, stepped up and took this young boy under her wing. Ever since Bella was incomplete without Sirius and Sirius incomplete without Bella, they were irrevocably intertwined. However, Bella was fire, Sirius a storm and even with the undying love that characterized their bond, the way they showed their affection was in the only way they had ever known and as their love grew stronger the thorns of the roses exchanged grew bigger and sharper, and they dug more and more into each other's soul, but even with the remarkably toxic nature of their relationship they never took it a sign to be less fervent for their love for each other instead they would break themselves and try to rearrange the pieces so that their two broken bleeding souls would become one, never mind the dangerous whispers of their minds that seemed to get worse and worse the closer in proximity they were (It was why Bella had never understood why her lord sought to divide his soul into several pieces when she only ever tried to make the fragments of two bodies join).
Later in life, when she killed her beloved cousin, she felt more like her lord than ever, having lost a piece of her essence that day. The only person who, no matter how foreign the concept seemed to be for him, was the only one who was (for the duration of his youth) unquestionably behind Bellatrix's rebellion. He would never allow his beautiful star to waste away and become another version of his mother. He would do whatever it took to keep the flame alive, using himself as fuel to feed his Bella. His and her hate of the same woman, no matter the divergences in the cause, was just one of the multitude of facets that linked them together. La folie à deux had never been appropriately used before describing this duo, Bella hated Walburga because Sirius hated her and Sirius hated Walburga because Bellatrix hated her(a vicious cycle that knew no end). Not once or twice did the tutors whom Sirius hated the most disappear, and more than once did the men who would talk ill of Trixie be found in precarious situations. They were always together, even when they were not (some less than moral magic made sure of that).
And so Bella was living proof that you should never meet your idols, and she and her star were the definition of not all love is good love. For all good things never last . But as all is with the black it was never as simple and once again their last name brought confusion, for they were always in the grey. She hurt him to make him stronger, he hurt her because that's all he's ever known. She hates Walburga for allowing herself to be a victim of this horrible fate (even though she had little to no choice) but decided to raise her child as a part of her soul. Furthermore, she envied the one who was but an extension of her magic for being a boy, because the world was open to him in a way it would never be to her. The thing she used to admire as a child would become the very thing she would be repulsed by later in life (no matter that her voice began to become higher with every passing interaction where she was diminished or undermined). All these clear indicators that later when a charming young man would present to her the concept of :
There is no good or evil. Only power and those too weak to seek it.
She would be mesmerized.