As usual, long backstory, but feel free to use them for any idea you have!

Enter Rita Duskfang, the gender swapped identity of Riot Nightclaw!

Riot's supreme confidence in his parkour skills had never been proven unfounded, and his track record in the street competitions of the RLD were unmatched. 683 races, 1st place in 675 of them, and 2nd in the remaining 8. He'd successfully outpaced contestants that could even fly. So when challenged by a local succubus for a high stakes race, he never for one moment feared he would have to pay the loser's toll. His self-assuredness was so unwavering that he didn't even bother to question the succubus as to what the defeat could cost him.

And so it was with devastating shock that Riot found himself suspended in midair just before the finish line of the race, unable to move the slightest muscle. He watched in confusion and anger as the succubus he'd left in his dust casually strolled over the line past him, even brazen enough to kiss him on the cheek as she did so. Seconds later he stiffly walked over the finish line to face his devious opponent and the reality of his defeat, however underhanded it my be.

The succubus pointed at him doubled over in raucous laughter has glared down at her.

"You handsome fool. It never occurred to you to stipulate any additional rules or regulations when facing an competitor that may have the ability to use magic?"

"I've only ever raced opponents with a sense of honor and competitive spirit I suppose. Even with your damn wings I had you. Just get on with it. What do I owe you?"

The succubus gave Riot an unnerving smile, "Probably another thing you should have negotiated before accepting the challenge isn't it?" she sputtered between a renewed bout of laughter.

"I have some magic I've always wanted to try, but it can only be used in instances like this, where a wager has been made. The price my dashing leopard is your cock and balls!"

Riot let loose a horrified grimace, slowly backing away and preparing to sprint as he never had before.

"Oh don't be such a scaredy cat, it's hardly what you're thinking!" she wailed through even more sputtering giggles.

Riot didn't wait for further explanation. In a flash he was already nearly at the end of the street before he felt his muscles succumb to that same, now heart-stopping freeze.

"I told you, there's nothing to fear. There won't be an ounce of pain, and by the end who knows, you may like the new you even more than the old!" she cooed from behind him.

He struggled in vain with all his might, helplessly suspended several feet above the ground as the succubus walked around to his front. Slowly, as though she were caressing a long missed lover, she gently trailed her right pointer claw down him from his chin to the tip of his cock. As she did, a strange but not un-pleasant energy trailed in her finger's path. Riot could feel his body undergoing some bizarre change as the magic suffused him. He felt the muscles in his and chest shift, as well as the with and depth of his throat. He could feel his legs and entire lower body also pulsing and shifting as it took on a new form. The strange feeling built until reaching a crescendo in a burst of dazzling red light.

Riot fell to the ground in a heap, trembling somewhat from the aftershocks of the magic as it dissipated within him. The succubus circled him inspecting her work, but he couldn't bring himself to look at her, not until he stock of exactly what had been done to him. Slowly, he examined himself, moving his hands over every part of his body. For the first few brief seconds he thought maybe the spell had failed, but then he felt his face and jaw. They were softer, narrower. His shoulders and arms felt more slender, but not weaker in any way, and he could feel without touching them that his hips and legs were the same. It wasn't until he shifted and tried to it up more that the first truly major change became apparent. A heavy weight pulled him down by the chest, as looked down to see the toned peck of his athletic physique had been replaced by a set of voluptuous, full breasts. He shout his hand down to his groin, to discover to his utter bewilderment that his cock and balls were gone, replaced by a plump soft slit, that immediately responded to even the light probing touch. Taking this change in for a moment, she shook the haze of shock from his mind and rose in a blitz to meet the succubus' gaze.

"What in the ACTUAL FUCK did you do to me!" he shouted, as he pointed down to he face.

In the act, he noticed the last of the changes to his body. His hands were also more slender now. Still large and strong, but with a fine and more dexterous grace to them now. His voice was also no longer a raspy masculine tone, but high clear and melodic. As he shifted to follow the succubus' movement, even felt the increased plumpness and bounce of his ass. His body still held a powerful and athletic tone, but it had also softened in certain areas and taken on a more feminine hourglass figure overall.

"I've simply taken my payment for our wager. I've always wanted to bend another's form! Don't wear such a horrible grimace. You're no weaker or slower than you were before the change. My magic has simply reshaped the flesh. And I must say, into something equally if not even more appealing. Full bouncy breasts, a soft and delicious looking pussy, and the positively smack-able ass look amazing on you!" the succubus swooned.

"Turn me back, right the fuck now you crazy bitch! This isn't my body!"

"Oh, but it is darling. For the foreseeable future at least. I couldn't undue this at the moment even if I wanted to. It's a pact spell. You would have to beat me in another race to end the magic's hold," the succubus said in a matter-of-fact tone.

"Then get your ass back to that starting line. We're-"

"Oh I think not dear, I've had more than enough fun for one evening. But I'll be around honey, if you can find me again, I might consider going for another little jaunt around the RLD with you."

The succubus let out a tiny giggle and began to hover into the air.

"Don't you dare! You can't leave me like this! What the fuck am I supposed to do now you insane fucki-"

"Sweetheart, I have a name, and it's not whatever you were about to call me. I'm Dusk. Ask around and you should be able to find me again at some point, Sweetthing. And as to what you should do, why, go out and explore that new body of yours! No matter who you see yourself as, breast are wonderful things to play with, and you might just be surprised and how much more you can do with a pussy than a cock!"

"You can be serious damn it! How the fuck am I supposed to speak with anyone I know, how the hell do I explain this!?" Riot shouted as Dusk lifted herself higher into the sky.

"That's part of the fun!" she called back down, "Re-invent yourself! You don't really look like a 'Riot' anymore to me...Oh! Rita, yes Rita sounds just right for you. I'll even let you borrow my name, oh yes, that sounds thrilling!"

"You really are an insane, sociopath bit-"

"So long for now! Until we meet again, Rita Duskfang!" Dusk cried out joyfully, before taking off into the sky.