Natasha attacked without hesitation, revelling in the way both Aurors screamed in terror and pain. She didn't, however, just kill the man. No rather she bit him, then bit him again and again, slowly bleeding him, causing him pain as she tore his robes to shreds.
She let him go then, bleeding, hurting, naked, letting him take to his feet, running away. She even let him take a few paces, before leaping after him, in two strides on top of him again, knocking him to the ground.
From behind her she could hear the other Auror's screams of horror and pain as she continued her game. Letting him run, then knocking him down, taking another bite - once tearing out some of the flesh in his arm at the same time. She swallowed it standing on top of him, looking into his eyes as she licked around her mouth. The man's screams were ear-piercing, delightful, and she did a dance of excitement as she let him go again.
Futilely, the man got up, crying, stumbling, hardly running at all as he tried to stumble away from her. If she could have frowned, she would have - he was no fun at all if he didn't run. Weakling.
She charged at him again, and this time she targeted him where it would really hurt him. His screams were impossibly loud as she tore his penis from him, laying down on top of him nearly crushing him with her weight, toying with his limb as he watched, eating it piece by piece as he wept in terror.