You aren't sure He has one

As you and Mary wait, you try to peer through the dense roiling smog in the stairwell. Whatever is happening in there, you know a great evil has afflicted your sister.

Father, hallowed be your name. Your kingdom come. Give us each day our daily bread, and forgive us our sins, for we ourselves forgive everyone who is indebted to us. And lead us not into temptation.

You repeat the Lord's Prayer as quickly and strongly as you can muster, and halfway through your third repetition, Mary shakes you by the shoulder.

You look up, filled with hope, only to have your heart sink. The smog is clearing, so you have a better look at your sister, but you almost wish you didn't. She is standing, back arched and arms at her sides with her fists clenched. Her head is thrown back as she breathes the smog back into her body. Carnal moans emanate from her suddenly-plump lips as the last of the smog enters her lungs and brain. Kristin's head lolls down and she moans again as her changes overtake her. Like a wave of red ink, her beautiful creamy skin is swept with corruption. Following the tide of evil, your sister's small teenage breasts swell. Reaching up with her talons, your precious sister shreds the last of her shirt and tears off her too-small bra. As her skin completes its red metamorphosis, Kristin rips off her sodden panties and clutches her swelling ass as her cock-like tail rams into her crimson pussy and bat wings erupt from her smooth back. As she raises her head, her wild jet-black mane falls over her shoulders and reveal the points of her horns. Then, and only then, does Kristin open her eyes. Her blue hopeful eyes are no more. What stares at you from what was your best friend and sister are two crimson slits floating in pools of obsidian blackness.

"Nice try sis, but this is too delicious to lose."