All characters involved are over 18 years of age.
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Stephine the witch smiled as she put the finishing touches on the ritual.
She was a cute young woman with short black hair adorned with a large blue bow that stuck out at an angle. Her slim body fit her tube top dress well, which came up just high enough to show her ample breasts. She had on long white stockings underneath, long black gloves that came up to her forearms, and a large witch's hat on her head with another big blue bow.
Closing the rune circle with powdered silver and myrrh would complete this summoning of a knowledge spirit. The other witches had warned her. But they could offer no explanation besides "it simply isn't done. The last time was three hundred years ago." She laughed. She had thumbed through hundreds of musty old tomes and done her research on hundreds of knowledge spirits. Every single possible precaution she laboriously added, every safety glyph known to her tradition. She had even double-checked them all for compatibility and added a good number of redundancies.
Why not just ask the beings that knew the most about magic? She was prepared for any of them that could pop up. What could the others possibly be afraid of if they hadn't even explored the possibilities? Easy peasy. It was even far from the most technical ritual she had successfully pulled off.
The witch adjusted the high hem of her form-fitting dress and closed the shutters on the cottage. She had arranged that the rest of the coven was distracted while this went down, but it never hurt to be certain. Her nose had grown numb to the burning incense that filled the room. Stephine picked her spellbook off the thatched floor and began the incantations. Ancient words, meticulously chosen over years of research, spilled past her lips. She felt as much as saw the glow of a successful calling permeate the summoning circle and carefully adjusted her pace of casting. Exactly as the ritual process specified. It was going just as she imagined and she felt the hairs on the back of her head raise.
She felt a burst of foreign information, surge into her brain, and grit her teeth. Some leaking was expected, but it just meant the spell had locked onto the correct type of spirit, right? The wind kicked up as power displaced matter into the circle, and fortunately, she had already secured everything. Her words raised to a fevered pitch as she called forth on the mightiest knowledge spirit that would deliver the magical power she sought.
The glow of the circle swirled and coalesced into a being: a giant white blob the size of her torso, more like a large maggot. This... thing wasn't on her list. It pulsated and turned to ooze on the runes she'd drawn. Impossible, her protections should have prevented physical contact with the rune circle! She sighed, this was a failure. Time to start over. She shook her head and opened her mouth to speak the reversal of the spell.
Then she felt a man's voice speak within the deepest recesses of her skull. She stiffened. Many such spirits communicated this way, but it jarred the first time it happened.
"You have asked for knowledge, young one. As you asked, so you shall receive. Every last drop of my knowledge."
She stiffed, at its deep, raspy tone. It certainly did sound old and it really might have been some kind of knowledge spirit, but... her hesitation cost her long enough for the maggot to coil up and burst into movement!
It landed on her face, knocking her over. Her slim, black-clad arms pawed at it, but its surface was too slick. She heard that voice rumble, "All of my knowledge, my will, and the rest of my mind. All this shall be yours. Rejoice."
Her screams went unheard, for she was alone in a dark, closed cottage. The large maggot forced itself in her mouth, and she felt her jaws distend to accommodate it. The disgusting white mass pulsed itself down her throat, and her attempt to spit it out failed on account of its sheer mass. It slowly disappeared into her as she kicked her feet and gave muffled yelps.
"Rejoice, young one."
She fought as hard as she could, shutting her eyes in exertion, but found no progress in expelling her unwelcome guest. None of her rituals or research had even remotely considered this. Her last thought before she blacked out was anger at how her peers were somehow right, and this was a horrible-
"Rejoice."
She shuddered and twitched as the creature completed its journey into her throat and her jaws closed behind it. The lump of its mass crawled down her neck into her chest and distended her stomach and chest. Her limbs continued to spasm and her eyes rolled up in their sockets.
Then she relaxed. The invader's bulk receded within her skin, leaving her looking as she had before the ritual, save much spittle and general dishevelment from fighting and thrashing so.
The short-haired witch opened her dark blue eyes. Something hidden deep in her gaze would have sent shudders down the spines of bystanders, were there any.
"Rejoice, as you have become a vessel to a much greater being," she said. She grinned, and stood up uneasily, as if readjusting to having two legs and two arms. After all, it was not Stephine who did so, but the primeval being known and feared only as Icthzhor.
Icthzhor looked down at the witch's extended hands through her eyes. She was slender, yet her breasts were wonderfully plump! He moved her hands to cup them. The grin he kept on her face got wider. Foolish young witches were shallow and abused their magic for vain purposes. Their figures were always perfect.