Test them on another student

Meredith woke up nude, as she always slept in the buff, but unlike most days, with a huge smile plastered on her stunning face. It wasn't an especially nice smile, though: this was a smile that promised mischief, humiliation, and malice.

Meredith knew exactly what she could do, and she had some pretty fair notions of what she would do.

As she usually did, Meredith had eaten a meal before bed that she knew would make her wake up with an overwhelming urge to defecate. She didn't have that urge now, her body being beyond any such biological necessity, but that didn't matter, since she knew she could simply create excrement in any amount she wished, of any consistency she wished, at any time she wished. Normally, she'd go to the bathroom and mope on the toilet, wishing it were one of her supposed friends' mouths instead of the bowl opening that she was doing her business in, but now that "consequences" was a meaningless term for her, she decided that she might as well relieve herself the way she'd always wanted to.

She thought momentarily about putting some clothes on, but decided not to. Nothing could mar her perfect body, after all, and if anyone tried to arrest her for indecent exposure, she could get out of that in any number of ways.

Her parents had bought her a nice house reasonably close to campus--closer than some of the official dorms, even--so there was generally a good stream of students walking by in the morning. Of course, she had her own personal chauffeuse (she made a mental note to change her job description) and normally didn't bother herself with navigating the crowd, but today she teleported down to the sidewalk right in front of the house and latched onto the arm of her intended victim.

"Mer--" she said before reality warped around them.

Reappearing in Meredith's personal bathroom, Christine Smith found herself buried to her waist in the ground, her hands affixed to the floor, and Meredith's gigantic ass hovering just above her mouth.

"--edith? What are you doing?"

"Open wide, Chrissie," said the rich brat, and Christine found her jaw locked in position as a torrent of shit rained down on her. Most of it went in her mouth, and she found herself involuntarily swallowing the vile stuff just to make room for the next load, but a good deal of it splattered on the rest of her, soiling her clothes, smearing itself down her skin from the cleavage she'd decided to expose that day.

"Now that," said Meredith five minutes later, "was the first good dump I've ever had." She waved a hand as she turned to face Christine, and terror radiated from the powerless mortal as she found herself rising up through the floor, only to be unceremoniously dumped on her butt into the pile of shit that had missed her entirely. To add to the indignity, Meredith turned around, bent over, and blasted out a thick sheet of crap, which draped over Christine and left no part of her unfouled.

Christine spat as she crawled out of the disgusting mess. But before she could get a word out, Meredith pursed her lips and blew at her, drying the fecal matter onto her. "You look like you could use a shower," the filthy bitch said mockingly.

"Actually I could," said Christine, trying to smile through the caked-on crap.

"Well, good, since I'm in the mood to give you one," Meredith replied, and instantly a strong stream of piss erupted from her crotch. Christine found herself hovering slightly, turning slowly in midair as Meredith drenched her in sticky, smelly urine. It mixed with the dried crap to leave her cold, smelly, and overall feeling defiled beyond her worst nightmares.

"Now, don't clean yourself off," and immediately any thought of doing so fled Christine's head. She had no idea that she even could. The concept was foreign to her; if anyone suggested it, her mind would reject it outright. "But tell everyone what I did." A nasty grin spread over Meredith's face. "Tell them I did it to you. Tell them I can do it to them. Tell them there's nothing they can do about it." She leaned in close to whisper, taking a long, satisfied whiff of her own excrement. "Tell them I'm coming."

The last thing Christine Smith heard as she was placed back on the sidewalk by Meredith's absolute command of reality was the young woman's cruel, anticipatory laughter ringing in her ears.