Lavender's eyes widened and she clawed at his arm as it closed tighter around her neck. He just shoved her harder against the wall and Lavender was losing focus as it got harder to breathe - she couldn't push him off and pull him arm away from her throat at the same time.
Her skin started to prickle and burn, like pins and needles spreading out across her body from her spine. Lavender gave a strangled gasp again, pulling more weakly now at his arm.