"Hello, hello! Oh, it's always nice to meet new people. I'm Myra! When I heard what you were yearning for, I followed it as quick as I could. What's your name?"

Alex does physically startle when his 'offering' goes up in sparks, followed by delighted cackling as he realizes it worked and he's got a live succubus before him, followed by intense blushing as he realizes he's got a live naked succubus before and his eyes hungrily wander across her body. 

She has large, glowing red eyes, with pupils shaped like a five petaled flower. 

pretty! (Alex had never even considered that her pupils might be shaped differently, and now he wants some of some his own, or her own considering the likely way things will go.)

She has breasts that seem to defy gravity, smooth and perky and just large enough to spill out of one's hands.

pretty! (He wonders how it'd feel to hold and grasp them, or to have gravity defying, smooth perky breasts of their own, which are grasped in another's hands)

She has velvety purple bat-like wings that spread wide.

pretty! (Alex wonders how it'd feel to be snuggled up against her wings.)

She has cute goat-like horns that poke from her forehead and curl back.

pretty! And can they be used as handlebars during sex.

She has pointy, elfin ears.

pretty!

And a penis, too.

pretty! and oh wow it's completely unfair that she has that too, Alex is extremely into it.

Hehehe.

She twists her hips a bit, leading to some swinging from her cock as it stands proudly. Then she leans forward a bit, wrapping her arms under her breasts.

"Like what you see, do you~? Hello, Alex. As you've surmised, yes- We can totally have sex. You can use my mouth and grab my horns, or tell me to bend over and stroke my wings... Also, I can turn you into a girl... And we can have sex that way too. However!" 

She places one finger on the tip of his nose, not hindered by the boundary of the pentagram at all.

"I'm not just going to snap my fingers and do it. For one, I can't. It would be terribly bad for you to have such drastic changes come in all at once. For two... I'll need to know what you want to end up looking like when all is done, and make adjustments as we go."

Her finger traces down over his lips and chin, then she giggles and leans back away.

"And finally at three, I'll want a down payment first. So... A gradual change sounds better, doesn't it? You'll become a woman a little bit at a time, more and more each day. We'll get rid of pesky hair one day. Work on your legs another. Your new breasts come in bit by bit... What do you think?"

That sure is some more desperately aroused staring from Alex as Myra ends up swinging her cock about with twists of her hips, and making her breasts look even more erotic as she leans forward and wraps her arms under them, followed by some enthusiastic nodding on his part at her first question.

"Yes! You're very pretty and unreasonably hot even accounting for you being a succubus! and those all sound nice to do-" and now he's BSODing as he thinks again on what it might be like to have a sex as a girl, but this time with the knowledge that Myra has a cock, which will almost certainly end up inside her.
Which he gets snapped out of when Myra places a finger on and traces against his face, and once she's done going over those points he responds.

"That all makes sense, and while a part of me is slightly disappointed that you can't just turn me into a girl right away, it does sound hotter to gradually get girlier each day... So um did you want your 'down payment' first, or to discuss what I'd want the end result to be? which I admittedly haven't really thought about in much detail before beyond 'cute girl'."

She smirks at his reactions.

"There's no hurry. I just want to make a couple things clear first... When I drive you to orgasm," she flashes a tiny smile and a small pleased sound, "And then, with my succubus magic, leave you still horny so I can do that again, and again... I am actually draining something other than cum. I don't want to lie about that, or hide it. It's a bit of magical essence, and I need it to sustain myself and do my own magic. It comes back on its own. Most people have very little, some have a bit more, and a rare few have a lot. You're in the second category."

Alex blushes and smiles back.

"Thanks for mentioning that! and I'd probably be fine with you draining all of my magical essence or as much as is safe to have drained, assuming you've also got succubus magic for handling or preventing any soreness that might normally result from being brought to orgasm a dozen times?" 

"It's safe. It mostly means you can't do other magic, if you've learned any, until it comes back. And I sure do. That's just a teensy tiny bit of healing."

She leans forward and speaks more quietly. The same scent of flowers and something husky and alluring is very distinct now.

"You'll want to hydrate before we start, though. Because 'a dozen times' is about right. You're in for some fun. I'm going to say... The whole process, start to finish, is going to cost you about one thousand orgasms. Up or down some depending on details. If you want to keep your cock, for example, that would lower it some."

"Great! And luckily I haven't learned any other magic yet that I'd actively miss out on, so feel free to drain me dry!"

When Alex gets another whiff of Myra's husky scent he lets out some needy aroused whining, before managing to get out "I'llgohydratethen!" and with a great effort of will forces himself to go hydrate instead of begging Myra to fuck him.

Once he's done that, he returns bringing along several bottles filled with water in case he needs to hydrate again later and says once he returns.

"I'd be fine with keeping my cock, or at least leaving the decision of whether/when to lose it to future Alex. And um, is there anything else we should discuss? I'm overwhelming horny enough that once you start doing things to my body I'll be stop being able to speak..."

"Heeee. Good planning. Our safewords are 'stop', 'safeword', or 'red'... It's only responsible to have one. If I'm doing something you don't like, say so. I'll do the same. We don't need condoms since I can heal away anything and can't get pregnant..."

She licks her lips, looking at Alex's cock.

"You know what, let's start your transformation early. It'll only make it better, the first step~ Do you want to keep any hair below your eyebrows and scalp? Or should I get it all? After that, the only thing left, is telling me how you want me~"

"Thanks! and 'stop' would probably be the easiest for me to remember, so let's use it for today?"

Alex shudders from arousal when he notices Myra looking at his cock, and wonders how it'd feel to have her mouth wrapped his length.

"That sounds great, and I'd want you to destroy it all, and afterwards you could suck me off, and guide me in how to return the favor after that if you'd enjoy that too?"

"Oh stars that's cute. Ah, I mean... Yes."

"Okay, here we go!"

Myra steps closer to Alex and raises her hands to his face. She begins running her fingers all over his face, tenderly and rhythmically. Over his ears, and behind them, and then over the sideburns and cheeks. All over his face, chin and mouth. Wherever she touches, it's perfectly smooth afterwards, when her massage-like motions continue. No hint of stubble at all. For that matter, no moles or other pretty blemishes either.

Then she starts trailing her fingers over his left forearm, carefully massaging the back of his hand, the knuckles of his fingers, up and down his forearm with light, stroking touches. She repeats the treatment with the other arm. And then the armpits, swiftly removing all the hair there, too, and moving on to gently stroking down his chest. Her face is very close to his, now, and her breasts idly brush against his front, occasionally. The tips of their cocks might brush against each other too.

...Now, does she actually need to touch every part of his skin that she wants to remove the hair from?

No.

Does Alex know that?

Also no~

His facial expressions at this teasing 'massage' will probably be pretty validating, Myra thinks.

"C-cute?" Alex squeaks out in an embarrassed questioning tone, before getting too distracted by Myra's touches to ask what exactly she found so cute.
Leaning into her touch as she rubs across his face, making a dumb happy smile and the occasional moan, not just from arousal but mainly simple happiness as Myra leaves behind smooth skin, free of hairs or any other imperfection wherever she touches. 

When Myra's face gets so close to his own, he finds himself tentatively trying to close the distance between them and kiss her.

Also once Myra's breasts brush against his front, Alex's moans turn more erotic and he finds himself wondering how it'd feel when (s)he finally has breasts of her own and what if they brushed against Myra's own, their soft mounds pressed together and squishing against each other.

Myra hovering her face close, lips partially open, looking at him with those glowy eyes full of desire... Would she refuse a kiss? Never.

Mwah.

She presses close, rubs one hand on the back of his head and one along his back, and plays with his mouth for a bit, keenly aware just how sensitive lips can be. Soft nibbles, warm breath, and that ever-present scent seem to sink into him. Her skin presses against him up and down, soft and warm. She continues working with her hands as the kisses continue, making sure to keep rubbing her hands and the rest of her body against Alex, smoothing his skin as she does. Hands moving along his chest, and then his abs, and his back, and then just above his crotch... And then pausing.

"You can tell me to stop teasing you, you know. If you want."

Alex delightfully leans into the kiss with Myra, gently trying to return the soft nibbles as well.
While also directing his hands to start trailing along her body, hoping to return at least of the favor of how good she's making him as she traces her hands along his body, starting by gently rubbing her shoulders, then slowly down along her back, followed by tentative touches against her butt.

And when Myra stops just above his crotch and says

"You can tell me to stop teasing you, you know. If you want."

Alex's wandering hands freeze and he sputters out "That's the teasingest possible moment you could've said that!!! though I don't in fact want you to stop..."

(She pushes happily into his touching, smiling and trying to encourage it with pleased noises.)

"Oh reaaaally? Aaaahn~" She quickly kneels and opens her mouth wide just before his cock, staring upward. Her breath brushes over the head.

(At Myra's encouraging reactions, he gets alot less tentative about his rubbing and tracing against her skin, and ends up groping her butt once his hands get there)

At the sight of Myra kneeling before him, her mouth wide open right before his, he instinctively thrusts his cock inside her mouth before he even realizes what he's doing.

(Her butt is very soft and gropeable.)

"Mmm!" Victory!

Her mouth is warm and slick. She outright moans in pleasure, before rubbing her hands along his thighs and bobbing up and down on his cock. She makes sure to stare up at him, lust in her eyes, as her lips move up and down, leaving obvious trails of moisture. Occasionally she pauses and swirls her tongue around the head.

Her horns are right there. Great angle. Very grabbable. Almost like they're designed for this position.

(Alex will have delightfully groped her soft butt then, and will later end up asking for a butt just as gropeable for herself)

She isn't the only one moaning from pleasure, Alex moans quite bit as he thrusts inside her mouth and gazes at her lust-filled face, and then a part of him wonders if he'll get to look like that in the future, a beautiful girl with lust in her eyes and a cock in her mouth as she looks up at the one she's sucking off.

Which throws him right over the edge into orgasming, with him grabbing Myra's horns to try and pull her down to the base of his cock as he blasts load after load straight into her mouth. 

Myra gently and patiently accepts it, her throat not really protesting at all. She wraps her arms around Alex's waist and swallows down each spurt and holds her head there for the long, long seconds until he's done- For now.

When she pulls away with a smirk, Alex's cock is still hard, and he's still horny- If not quite as unreasonably horny as he was in the buildup to orgasm moments before.

"Good girl. Or is it boy? Please, let me know what you prefer. Still. Delicious." She kisses the tip of Alex's cock. "Mmm... You wanted to return the favor next, right? I think the best position for that is me sitting on your bed. We can lay down pillows for you to kneel on."

It's a bit weird to still be horny after the most intense orgasm of his life so far, but the pleasant kind.

"I'm still a boy but being called a good girl felt really nice..." Alex blushes quite hard, both from what she just admitted, and from processing the fact that quite soon he'll have his mouth wrapped Myra's cock. "thatmakesenseI'llgograbsomepillowsnow" he says before grabbing them.

She hugs him from behind as he's grabbing pillows, just standing there like that for a moment.

"You can have nice things. I'm looking forward to making you a beautiful girl."

Then she calmly sits in position on the bed and spreads her legs wide for easy access.

"Take it easy, okay? Don't push yourself past what your body is comfortable doing. I'm designed from the ground up for sex- You're not. Yet~? I kid."

"T-thanks, you're so nice and I'm really looking forward to that as well."

Once he finishes gathering up and laying down pillows, he returns her earlier hug, and says as he moves to kneel down in front of her.

"Don't worry I won't push myself! ...is that an option? becoming designed from the ground up for sex I mean?"

"...Mmm. If you're wondering if you can become a succubus, it doesn't work like that. But continuously changing your body to be better at sex, to enjoy it more... Is something you can do. Please think hard about it when you're not horny in front of a succubus before setting on that course, though. We really don't like pushing people too far. Succubi who do that give the rest of us a bad reputation."

She pats him on the head and runs a hand through his hair.

While talking Alex happily nuzzles into Myra's patting of his head, and tentatively begins to rub his hands against her cock, her pretty unreasonably erotic cock.

"I wasn't thinking about specifically becoming a succubus as that'd probably be farther in that direction then I want to go, but having a body that doesn't get in the way of the things i want to do, that's more capable of enjoying the things i want to enjoy, that's something I'm pretty sure I'd want even when I'm not incredibly horny in front of the prettiest girl I've ever met. But that's more a conversation for future Alex when she's discussing what body she wants, for there's a difference use I'd much rather put my mouth to."

Followed by beginning to kiss and lick Myra's cock with much less confidence then his previous statement might imply.