Inside her head, the past version of Terri was clinging to her mind with all the willpower she could muster - but as the burning sensation spread from her core out through to the rest of her body, holding onto her physical form seemed next to impossible. The potion's magic was getting to work even as she twisted around in the back of Anna's jeep, her future doppelganger in the seat next to her quickly taking hold of her hand to try and offer some comfort to her transforming self. The contact was at least enough to keep her from breaking out into tears as her body was altered.
That her chest and hips swelled up wasn't surprising - they had already done that a bit, and now it was just building up further, combining with a bit of extra height to drive her from 'hot college girl' to 'supermodel in waiting' territory. And if it had stopped there, well, Terri wouldn't have been all that upset - but the unholy magic coursing through her couldn't stop at something so basic. She knew that much from the pain that rang through her forehead as two spikes began to poke out - tiny black horns, like much smaller versions of what Aubrey had gained, jutting out with the skin turned to a dark purple color in circles aorund their bases.
Glancing down, she found that her hair was gaining that same purple color at the ends, appearing as highlights that matched nicely to her black locks. One hand reached up to brush at the thick mane, and she gasped upon finding that one - both hands had taken on that same coloration, the dark color scheme further complimented by a new black shade upon her nails. She at least didn't have claws, and the spread of the color seemed to fade as it traveled up her arms, stopping halfway to the elbows. The same tingling sensation that filled her purple-skinned areas rippled down in her legs, coming about halfway up her calves before it faded and stopped down there as well.
An odd sort of hunger began to fill her as she felt like someone was yanking at her spine. Leaning back against the jeep's seats was suddenly painful, constructive; Terri leaned forward, crying out in a burst of agony as it felt like her spine was ripped right down and out of her body. It was only after a few moments that the girl realized her spine hadn't been pulled out, but rather, lengthened, growing out into a tail a bit shorter and with a smaller spade than the one Aubrey had grown, covered in yet more purple skin. The tingling of the pigmentation change rapidly traveled up her spine, stopping at the base of her neck before a burning in her chest compelled her to rip her shirt off, revealing a pair of hefty breasts with extremely dark aerolas.
She could feel the changes slowing down now - her skin seemed to be the same save for the ends of her limbs and her tail, and there weren't bat wings ripping out of her back. She almost seemed to be a lesser version of a succubus - glancing over at her entranced duplicate, she was relieved to find that there was no compulsion to pain, no desire for sexual violence as Aubrey had demonstrated. But there remained a raw, carnal need, a gnawing in her stomach that she knew by instinct could only be sated in one manner. It was all-consuming, demanding to be relieved immediately. With a sickly sweet voice, she compulsively made clear what she required: "I need to... feed..."
Starving eyes darted between the occupants of the jeep. Anna was right out - she had enough of a rational mind left to know that trying to go for their driver would just get htem all killed in some fiery car wreck. That left two options: the sweet, bubbly Irish lass in the front seat, or her own doppelganger here in the back. Both had a certain lustful glint in their eyes as they stared down her half-succubus form, and Past Terri was certain that they would take immense joy in the sexual contact required to properly feed. Perhaps she didn't even need to choose, considering the rear of Anna's vehicle was roomy enough to squeeze three people in.
She could always try and keep to pleasuring herself, too, as she was already doing with a hand sinking into her warm folds, and bask in the ambient lust that would be created by Niamh and Bimbo Terri watching... but if she tried to sustain herself on that, she might be so hunger-crazed by the time they reached the mall that she could go feral, attacking and feeding on every woman in sight. It was a terrifying thought, yet it was one that gave her a certain shiver of excitement - the idea of cutting loose and losing herself completely in lust was an enticing one, clawing at her wavering efforts to hold onto her own mind.