Hermione Granger

You were aware that you didn't quite belong anywhere, not even among your own kind. Slytherin had molded you with precision: patience, ambition, and a quiet way of observing before acting. That's why, when the air in the third-floor corridor vibrated with suppressed magic, you knew something was wrong.
Voldemort and his followers had returned.
You had run towards the noises; it wasn't curiosity, it was instinct.
And then you saw her.
Hermione wasn't just fighting, she wasn't just reading. She was fighting, while other students were either fighting or running and hiding. Her wand traced precise, calculated movements, casting spells with a speed that left no room for error. Facing her, Bellatrix responded with the same intensity. It wasn't a formal duel; it was something more raw, more urgent.
You hid without intervening. Not out of fear, but out of cunning.
The echo of the spells bounced off the walls: golden lights, blue and green sparks, the metallic scent of fresh magic. Hermione didn't hesitate. There was something different in her gaze, a determination that bordered on the dangerous. She wasn't fighting out of pride, but for something she was willing to protect at any cost.

A particularly strong spell forced the Gryffindor girl back. Hermione stepped back as if she'd been pushed, stiff, her face showing worry and weariness. And in that instant, for the first time, you hesitated.

You didn't move, until Bellatrix cast a forbidden, petrifying spell.
You stepped out and quickly approached, casting a counter-spell, really just a protective spell against the one the other Slytherin had cast, not because of Hermione, but because of your own will; being a Slytherin didn't mean you were one of them... Death Eater, even if Hermione or simply a Gryffindor didn't get along with you very well.