Realized when mention Gabriel and Clair in the last few I replace Britney with Jenny. Sorry for any confusion caused by this.
They were on the edge of the large open center waiting for the spell to hit. They were glad that this year only 18+ people were allowed. Other years there was many issues with adults who wanted to explore their bodies and kids in the same place. Emily and Kyle saw to their right an elderly couple, they decided to strike up a conversation with them while they waited. The elderly man introduced himself as Paul, he was dressed up as a large cocked minotaur, his wife Milly was dressed as a sexy four breasted holstaur. Milly and Paul told them that they wanted to have one last good romp. Milly answered Emily's question for why four breast with, she didn't want an udder but still wanted to be more cow like.
While Emily and Kyle were talking to Milly and Paul, Gabriel decided to follow suit and strike up a conversation with the people next to him. There were three girls in a three bodied transparent orange suit with a multitude of breasts and arms. They introduced themselves, Hailey, Kimiko and Nina. They explained their costume to Gabriel, they were an slime goddess of love, their slime was more akin to gooey lava or gooey fire to represent the heat of passion, love and sex, hence why it was orange. They wanted to be in constant sexual heat and fuck themselves. Gabriel told the girls their plan, Britney and Clair moving the dragon heads and speaking up. The girls blushed a bit, but manage to recover.
Everyone then went silence as in the dead center and using microphones the Shapers began the ritual spell. Some time passed and everyone was on edge as the chanting was reaching its end and the spell would be cast. just minutes before however from two different spots in the stadium came yelling to stop the spell. The two different people yelling ended up yelling the same thing, they were caretakers and their charges were suffering a heart attack. It was unfortunately to late the two people died while the spell was cast, overcharging the spell like incident that brought magic and Shapers to the forefront. Unlike last time the spell wouldn't effect the whole world, the Shapers spent many resources to create a barrier in the stadium and another one in the city, ensuring that even if the barrier at the stadium would fail the one around the city would ensure any supercharged spell would not effect the world.
The Shapers quickly realized that the barrier around the stadium leaked the spell a bit into the city, but it also caused the supercharged spell to bounce around the stadium effecting the Halloween goers in ways they couldn't really predict.
Emily and Kyle felt a tingle throughout their body as the spell began to change them. They had expected to have been changed instantly but now this overcharged spell is changing them a bit slowly.
Emily felt Kyle cock merge with her ass, their hips merging into one and their legs becoming that of a horse. Emily felt Jenny's head merge with her and Kyle's new rear, turning her rear into theirs. The costume quickly became real as their bodies merged with it, dark brown fur now covering what was once fake brown fur. As if to make it clear to them that the spell was over charged, since one of the concept of their costume was merging they sucked in Milly and Paul into their changes. Emily felt Jenny's mind settle in their new large horse cock, a short while after Emily felt a second cock come into being. This cock was that of a bulls and was occupied by Paul's mind.
Emily felt the four large balls drop down, hanging from their rear. Milly's head came into existence next to Emily's and Emily's torso grew a second pair of tits giving her four. Their tits swelled in size becoming E-cups and began leaking milk out of them, the tits were then quickly covered by a cow print bikini. On top of Kyle's head grew a pair of bull horns. Emily and Kyle's torso grew a second pair of arms and hands, while their equine lower half grew a couple of anthro horse arms. The three human heads turned to see want was going on with their mate Gabriel.
Gabriel felt a tingle run through his body as the spell began to affect them. The three college women he was talking to collided with him and he felt as his body began absorbing them. The tits on his costume became his and began to swell in size, it grew till it was J-cups. Clair and Britney along with the dragon taur costume merged with him now her. Her frontal hips widened out into womanly shape, Clair and Britney's dragon heads coming out of her hips. Two more heads grew out of her frontal hips, they were Nina and Kimiko. Britney and Nina where coming out of her left hip, while Clair and Nina were coming out of her right hip. Gabriel felt her torso enlarged as she became a proper demon lord/queen. Her belly became harden with a 8 pack ab and below her large tits 2 more pairs grew giving her six tits hanging above her rock solid abs. Her hair turned into hot semi-translucent fire slime which flowed down to above the were she merge with her dragon lower half and flowed over her tits to cover her nipples. A pair of large demonic horns grew out of her head.
Gabriel felt as Hailey became her now sentient dragon pussy. Her pussy altered to be ready to take the double cocks of their husband Kymily. Ten large draconic tits grew out of her lower half, instead of the 6 originally planned and 6 crotch-breast came into existence instead of four. Draconic arms grew out of the side of her taur half, while six arms grew out of her torso.
Gabrainey could feel her fertility and it was driving her crazy, she needed to be bred, her pussy began drooling at the though of taking her husbands cock.
Gabrainey and Kymily felt the magic dissipate, not stopping them from changing more but preventing them from merging with others.
Kymily could smell their wife's need, without much thought Kymily mounted their wife and began breeding her. Kyle wrapped his arms around Emily's large tits while Emily wrapped her arms on Gabby's now lactating tits, playing with her nipples while Kyle played with hers. Emily and Milly moaned, while Kyle grunted. Kymily wrapped their anthro taur arms around Gabainey's dragon lower half and began playing with her tits. Kymily realized they had enough arms on their lower half to play with all of Gabrainey lower half tits.
Gabrianey felt Paul and Jenny start to hit the entrance of her womb. Gabrianey felt as the people in the stadium fell to the lust emanating from her from the power she inherited from Hailey, Kimiko and Nina's horny slime goddess costume.
The Shapers did their best to manage the situation before them by alerting the people in the stadium that during Halloween they cast a spell on the stadium to make it bigger and have private rooms for such lustful activity. To prevent things from getting out of their control they began to cast a spell to ensure that no one can leave and to make the corridors into a maze. They knew that they wouldn't be able to turn most people back, but they would do their best to help eliminate the primal urges caused by peoples costume.