It was difficult not to gloat when the weight of power in the room was so heavily shifted in her favor. She had the weapons, she had the magic, and she had the skill. She also had the element of surprise, which is why the pudgy man was cringing in the corner of the dark room with no one there to protect him.
It was the moonlight coming into the window that she hadn't considered, though. She stood silhouetted against it like a black, avenging demon; her leathery wings folded against her back making her appear taller, more intimidating. She could see the fear in her target's eyes and knew what an imposing image she struck. There was a coiled, thorny vine in her right hand. She opened her fingers and let it unwind.

Snapping her arm up, the whip jumped. Then the explosive bounced off of the window sill behind her, flipped gently through the air with the whir of metal friction on air, and exploded at her back. The room erupted in light and noise. For a moment, there was only orange fire and her long, black shadow stretching out across the room and up the far wall. Then the room went black, the sound ceased.

The assassin's wings were set ablaze, holes burning with orange ember outlines like dead leaves tossed on coals. The pain was immense, but knowing that her wings were gone forever was much more incomprehensible. She stood in silence, her expression of shock so intense that her facial muscles began to cramp. Tears welled in her eyes and streaked down her cheeks, but whether from pain or horror you couldn't discern.

As the last membranous patches of her wings withered and curled against the soot-blackened bones, the man she had been sent to kill found some courage within his cowardly heart to stand, to throw open the door, to run down the hall.
The assassin's whip dangled from her grasp, fell, flopped to the floor. This kill would have made her a queen among her people. Now, without her wings, she could never return to them.