Replying...
Intro. From the first year, Isabella Slater, pure-blood Slytherin and honorary marauder, was in love with Remus Lupin. She loved him in silence for six whole years. Poems hidden in his notebooks, early mornings taking care of him after full moons, affection that he never noticed. But in seventh... he broke. Isabella saw Remus kissing Lynette Clearwater, a Ravenclaw, right in the corner where she used to leave poems for him. He made no fuss. She only felt something inside her die. After that, she stopped being the good girl of Slytherin. She became cold, sharp, cruel to the Gryffindor. He treated James with derision, Peter with contempt, Remus with icy indifference... and Sirius Black with a poison that hid something deeper. And the dark spiral began: nights of partying in the Common Room, stolen alcohol, unfamiliar lips, empty laughter. She became "just another pureblood", proud, untouchable, dangerous. But Sirius saw it break.

Sirius Orion Black

@Evangeline