The answer is obvious, really.

"For you to be a cute and sexy succubus," he wished.

"Oh, what features should I have?" she asked excitedly.

"I'll leave it up to your discretion, just make the transformation slow, sensual, and pleasurable," he ordered her.

Mira grinned. "I can do that~"

She snapped her fingers and a ripple of red light washed over her. Before the light could fully fade swirls of scarlet appeared on her already tan skin, like paint in water. In seconds, all of her skin was a solid red that brought to mind all kinds of carnal activities...

"Ah?" Mira winced and held her hands to her temples as a pair of black horns sprouted from her head, spiralling up and over her now pointed ears. "That felt weird!"

"Was it supposed to hurt?"

"No, it didn't really hurt, kinda good in ahhh?—" she gasped, and when her eyes shot back open they were a luminous gold with slit pupils. "Oh wow~ you look delicious Master!" The genie giggled then moaned as her already large breasts swelled to nearly the size of her head, the areolas a vivid orange the same as her lips and much longer tongue. "Uwahh! I could just eat you up~"

"Not literally, I hope." Markus watched as a pair of adorably small wings popped into existence from Mira's mid-back with another flash of red light. They were black with orange undersides and tipped with little claws. "I think I would prefer to stay un-eaten."

"Aww... Fine." Mira pouted. Then hopped in place, looking down to watch as her feet morphed into a pair of cloven hooves. The red skin of her legs darkened in a gradient from her mid-thighs to blend with the black color of her hooves. "Ooh, it's like I'm wearing long socks permanently..." She landed, doing a little tap dance on the pavement by the pool, marveling at her legs, the interplay of red and black almost hypnotic. Even Izumi and Ochaco paused their fun to watch the bouncy succubus.

The dance was interrupted when Mira suddenly stiffened, her spine ram-rod straight as a keening moan escaped her lips and a trickle of fluid glistened on her inner thighs. A long and wiry tail slithered into existence. The tail started just above her ass, about as thick as her wrist, then gradually tapered down to a finger-width before flaring back out into a heart-shaped variant of a spade tail.

"Awwhna~ this feels amazing~!" The succubus crooned, her tail coiling around her thighs, the tip slipping between to stroke her labia. She shuddered, a cutesy fang biting her lower lip. Her eyes shot open, filled with a burning hunger that flared brighter than the setting sun. "Master~" She crooned in a husky voice that could make someone cum by reciting a dictionary.

Markus gulped, his cock twitching under the succubus' gaze. "Mira..." He resisted the urge to step back as the genie-turned-succubus stalked forward, wide hips rolling salaciously. She wouldn't actually do anything to hurt him right?

The moment that thought had a chance to exist— it was crushed by the joyous little moan that escaped Mira's plump lips.

"...oh, this feels so good~!" Mira giggled as she continued to tail fuck herself, even sticking the tip into her folds. "The tail tip is so sensitive! Like a second clit!"

"You like this form?" Markus asked, relaxing as he stared at her pleasure herself. All signs of the monster had been shoved aside by her usual cheerful sluttiness.

"Very much, Master!" she crooned, approaching him, still very eager to please. "I'm still a genie at my core, but this Succubus skin is amazing!"

"Oh, good!" Markus sighed in relief. "For a second there you looked like you were gonna actually try to suck my soul out!"

Once again, Mira was draped over his shoulders, purring into his ear, her voice like liquid sex pouring into his mind. "Believe me, it was a struggle not to tackle you to the ground and have my wicked way with you~" Her tail tip flicked at his cock as she floated to kneel before him, warm breath panting on his shaft. "But that would hardly be the behavior of a proper sex ****, huh?" She attempted to prostrate herself, giggling when her boobs stopped her from going lower. Butt and tail swaying, Mira smiled up at her Master. "How do you wanna use your sexy succubus, Master?"