obsessed with the idea of potter!reader who after james' and lily's death and the incarceration of sirius, goes absolutely, murderously, insane. like a full flip to the dark-side, hunt down and slaughter everyone who had anything to do with it, which then leads to killing any death eater she comes across, spiral into madness.
a ravenclaw who was once lovely, kind, and brilliant and had vast knowledge of dark arts from the books she had read over the years, never shying away from them because knowledge is knowledge and reading about dark magic didn't mean using it, then turning against those ideals in a manic rage and becoming a threat that no one was ever prepared for.
and obviously at first she's a little shaky with it, a little amateur, but over the years, she learns. She commits herself to it like she did everything else until there is mastery in the way she wields dark magic, mastery in the way she hunts down those she hates, because when she comes for them, there is never a chance of them making it out alive.
she will not let a single one of them slip through the cracks the way peter once did, she will descend upon them like a plague until she has covered them all, until there lives are nothing but fear and agony and death.
and despite it being death eaters who's bodies are being found more and more often, the ministry and the order cannot just allow someone to run around britain, murdering as they please and with the use of such horrific magic, but she is difficult to track and impossible to pin down. She's always had a knack for disappearing and never being discovered unless she wanted you to find her.
but there are exceptions to that skill of hers, three if you want to be specific.
one of them lies cold in a grave in the town she once called home, his death the very reason for the monster she has become.
the second has never been seen since everything fell apart, and she knows he's not dead, he was her best friend once upon a time, she would have felt it the moment it had happened, but now all she feels is the dull sting of his abandonment.
the third sits rotting in a damp riddled cell, chains chafing at his wrists and horror wrenching at his heart as an auror tells him what has become of the girl he once loved before there is the rattle of keys in the lock and his door swings open.
because who could be better at luring her to them than the man who everyone is convinced had a hand in the murder her brother, who would be better at tracking her if she didn't come than the man who had once been inseparable from her side as if there were a string upon both their souls that he was incapable of not following.
who better to find a potter, than sirius black.
