No, Selena decided. As hot as Diana was, Selena just wasn't the kind of girl who was into incest. There'd be other buff wolf chicks out their. Hell, she might look like that herself eventually! It'd take a month, but it would actually be kind of fun to watch her changes grow steadily more drastic over the next month as Diana's slowly diminished into nothingness.
"Fuck, am I hot!" said Diana to the room. "Think I'll let myself sweat for a bit." She shifted to her human form. Her muzzle dissolved into a human nose and mouth, her tail sank back into her ass, and her claws shrank back into harmless human nails. "Damn, it feels good to have sweat glands again! Shame to ditch my fur, though."
Selena chuckled under her breath at that. Time to spring into action. She bounded over to Diana and took her sister's hands in hers. "Wolf thou art, but wolf no longer!" she chanted. "Thy wolf is mine, to make me stronger!"
Diana tilted her head in confusion. "The hell? You been smoking weed with Jezebel again? I swear, that succubus chick is such a–"
Diana and Selena suddenly both jumped as an electric jolt surged through their bodies. Selena knew it had to be the spell working.
"What the fuck was that, Lena?!" Diana yelped.
Selena tried not to smiled triumphantly. "Oh, nothing. I better go now. Mom'll want me to wash the dishes."
"Go ahead," said Diana, lazily scratching at her pussy hair. "I gotta prepare for tonight's hunt. It's the full moon, ya know. Not that means anything to a dud wolf like you." She snickered to herself.
"Says you," said Selena. "Actually, I really enjoy full moons." She did now, at any rate.