Disclaimer: Not mine, of course. I created the character of Marianna Thorpe, however, so feel free to use her, though I don't know why you'd want to! This is simply the story of Bellatrix Lestrange, after the use of her first unforgivable curse. I don't know if it seems out of character, but I don't think that you can kill and not feel some remorse.
Always a Black, never a murderer. Until today. They say that you have to mean an unforgivable for it to kill, but she knows that isn't entirely true. A two word spell, that's all it took, and Marianna Thorpe screamed no more.
That had been the worst bit. Her screams. They were piercing, slowly ripping at her soul until she could do nothing to stop a tear rolling down her cheek.
She rose from the cold, hard floor, and turned to face the mirror. Her black hair was bedraggled, and her dark eyes were dull. Innocence had no home there anymore, not like when she was younger, playing with Cissy and Dromeda. She was happy then. When she went to Hogwarts, she realised what her parents had been doing all those nights, when the people in black robes would show up, and she and her sisters would be shut outside. She was proud to be the daughter of such important people.
Several years later, when her parents disowned Androdema for marrying a muggle born, she was the one who witnessed her mother blast her face from the Black family tree. She did not try to stop her. She already had a dark mark burnt into her arm, and she simply laughed as she recited the story of her traitor sister to the Dark Lord. Her Dark Lord.
That was only a few weeks ago. The Dark Lord had not sent her out to kill, until today. Marianna Thorpe, eighteen years old, just out of Hogwarts. A blood traitor, just like her sister. She supposed that's why her Lord had chosen her for that particular task.
And, ever obedient, she had done what was asked of her. She had killed her.
She looked at her hands. They were red, and damp with blood. She scrubbed and tore at them, but the blood only thickened. It would not come off. It was covering her skin, smothering her whole body, choking her slowly.
She stood in the shower, her eyes clamped shut. The water was hot, too hot, scalding her body. Burning away the blood, and the sin, and the remorse.
All alone, she cries. Her tears feel hotter than the red hot water of the shower, as they slide down her lean cheeks. She cries for Marianna Thorpe. She cries for her sister, whom she can't speak to anymore. She cries for the marriage she undertook to make her mother proud. She cries for the future deaths she knows she will cause.
She cries for death and for pain and for heartbreak. She cries for herself. She cries because she knows she will kill again, and because she fears she will grow used to it. Grow to like it.
She cries, because she knows she must never cry again.
Bellatrix Lestrange. Always a Black, forever a murderer.