It has the perfect opportunity!

"Hey Yang, do you have some kind of incense or something you forgot to put out in your bag?" Ruby asked, pointing.

"Eh? No, I didn't bring incense, what are you- what the fuck!?" she demanded, checking her bag and finding a trail of violet, glittering mist emerging from it. She opened it, finding the lamp inside, the mist coming out of the spout. She scooped it out, which turned out to be a mistake. Albeit one she would be glad she made later, but almost immediately, the trail turned into a deluge of mist, engulfing her. "Hey, what the fuck!?" Yang shouted, trying to move away, dropping the lamp, but found herself unable to get out of the mist, like she was physically unable to move past a certain point.

"Language!" Ruby said, thinking it was just some kind of normal incense smoke from something burning inside the lamp, comically missing the gravity of the situation.

"Bite me! And help me, this mist isn't normal!" Yang yelped as it lifted her up in the air, her figure barely visible within the cloud.

"Eh!?" Ruby started to panic, before activating her Semblance, and rushing at the smoke, intending to pass through and grab Yang on the way out. However, she somehow bounced right off of it, and crashed head first into the metal wall of the room. "...ow..." she whined, swirls in her eyes.

"What's happening!?" Yang growled, thrashing as much as she could while in the air. "What- oh..." she moaned as a sense of tranquility began to pass through her mind. She was suddenly feeling... Good, content, like everything was perfectly fine. She tried to fight off these feelings, clutching her head, but it felt so seductive, good even.

She yelped a bit again when her clothes started to dissolve, but instead of outright rage, she was more startled, and briefly annoyed before her mind calmed once more. As she was stripped bare, the mist somehow seemed to massage her mind, working all the stress and anxieties from it. It delved into her sexuality, tying it to her thrill seeking tendencies more firmly than it already was as sensual thoughts played out in her head. She shivered in delight as she stopped fighting entirely, letting the mist do its seductive work.

Next came the alterations to her body. Some of the vapors began to seep into her very skin, causing her to jolt slightly, but it wasn't unpleasant. Quite the contrary, actually. Her skin smoothed out perfectly, all hairs on her body save what was on her head disintegrated, seeming to turn into more of the mist. "...you better leave my beautiful mane alone," she growled, the idea of her hair on her head being removed actually making her angry despite how much she was enjoying this so far. The mist didn't respond, simply removing all blemishes on her skin, from a small birthmark on her hip, to pimples, and even some moles and her training scars.

Ruby got up, shaking her head to clear the cobwebs, before seeing the mist still present and Yang's silhouette floating in its midst, her back arched. "Shit, Yang!" she shouted, immediately bringing out Crescent Rose in scythe form, and swinging it at the mist, careful not to have Yang in its path. Predictably, the blade went right through the mist, but didn't disturb it in the slightest.

Yang gasped as more seemed to sink into her sizable boobs, expanding them just a tad. She was already busty, so only a slight enhancement to the size of her girls was even considered. More of the vapor swirled around her pelvis, enhancing the flare of her hips in addition to that. Her abdomen tightened a bit as some excess fat melted away, though it barely was noticable. All in all, her body was already so hot, the lamp really didn't seem to have much it wanted to improve.

Then it decided to alter her hair. Yang gave a small yelp of protest, before realizing that it wasn't removing it like it had her body hair, but instead altered the texture, making it more silky, while maintaining the slight curls, and adding more shine to it. Furthermore, it added more natural luster to each and every strand. Now, it resembled a river of gold, cascading down her back.

Then, jewelry began to form. A golden collar materialized around her neck, containing a single large amethyst encrusted in it. Similarly, her wrists were bound in tight, but not so tight as to restrict blood flow, wrist bands, also encrusted each with a glimmering purple amethyst. Her head gained a circlet as it formed out of thin air, and her ankles were bound in bands as well. Her toned biceps were the final touch, each gaining gold bands around them.

Then came the clothing. Fine, sheer Violet silk often found on Vacuo exotic dancers began to form on her body. A sleeveless top materialized on her chest, leaving her midriff and a healthy bit of cleavage bare. Around her lower half, poofy pants came into being. From the bands on her biceps, detached sleeves flared out, and attached by the corners to the circlet, a veil covered her lower face. The silk was amazing, comfortable, caressing her skin sensually. And quite sexy too, given it was essentially transparent, leaving nothing of her form to the imagination.

Then, the sensations running through her intensified in her feet. She looked down, seeing her toes begin to disintegrate, turning into more of the purple mist and yet... She could still feel them, and they felt amazing, albeit odd, not quite like toes anymore. More like the nerves were being distributed amongst the mist surrounding her. The mist moved up, consuming her feet, and then her calves, followed by her thighs, before finally ending at her hips, stopping just at her midriff, the transition from flesh to mist actually looking smooth and seamless. The mist around her then fully coalesced into what seemed like a long, sinuous tail made of it, attached to her torso, and the other, thinner end firmly attached to the spout of the lamp.

She could actually feel the tail like it was fully solid and part of her body, and she was able to move it on instinct, taking moment to experimentally undulate it, even tugging with it, but was completely unable to detach it from the lamp, or even move said lamp. "Okay, I'm stuck," she remarked, but not panicking, even as she used the tail to pull harder, but it felt like she was trying to move the earth itself.

"Y-Yang?" Ruby asked, staring slack jawed. "What happened?"

"Not sure, but it feels great~!" Yang crooned, looking herself over. "Not to mention, I look smoking hot now! I mean, I always was, but now I'm even hotter!"

Ruby had to agree with that, looking Yang over. She had always been attracted to Yang, though she tried to suppress such thoughts. "No, bad Ruby, bad thoughts!" she immediately shook her head, and slapped herself repeatedly and rapidly, trying to banish attractions that threatened to resurface as she berated herself. "That's your SISTER for Oum's sake! Half sister... But still! But she's so hot! No! Such thoughts are forbidden!"

She was so distracted by the mental war, that she didn't immediately notice when Yang started to be drawn into the lamp, and let out a murmur of, "Oh~." When Ruby did notice, she panicked.

"Yang!" she cried out, diving for her shrinking sister, but was too slow, and Yang rushed into the lamp, entering with an audible pop.