He let out a sharp bark of laughter, blocking the blasting curses with a wave of his wand, ducking the ropes that shot from her wand long enough to cast his own counter-charm. It sent the ropes back at her throat, this time as hissing, writhing snakes. It seemed appropriate. He followed that with a blasting curse of his own; not at her, but at the bricks beside her, hoping to distract her, perhaps even knock her out.
"Is that all you've got?" He remarked, almost casually, then tutted. Perhaps it was stupid to taunt the Death Eater, but while Fabian was a Ravenclaw, he was also a redhead. There were times that temper, that little thread of impulsiveness, got him into trouble. Unlike his brother, Fabian spent his life behind a desk. He had made sure that was no excuse for becoming rusty. He worked just as hard as the active Aurors at duelling and defense, and there was no way in hell he was letting this woman walk out of the street alive and free. He didn't much care whether she was dead or arrested.