I'll add my backlog of prompts onto the pile of ideas. I'm not getting around to them any time soon, so they might as well inspire someone else.

Frozen Solid

(Disney's Frozen, f/f, freezing, shattering, non-lethal)

Set in the Frozen universe.

Several months after the events surrounding Elsa's coronation, Anna confronts Elsa about still avoiding her and stopping any use of her powers as soon as Anna approaches. She wants Elsa to see there's nothing to be afraid of. She asks her to freeze and then unfreeze a flower, which works just fine. After much convincing, Elsa finally agrees to take things one step further and freeze Anna's hand. Anna starts dancing around and hitting things to show how sturdy it is.

"See? Solid as a..." A sound like glass shattering filled the air. Anna looked down at her hand - or, rather, where her hand used to be. Her arm now ended at her cracked frozen wrist. The fragments of her hand were spread across the table. "...rock. Uhhh... oops?" It took a few seconds for the consequences of what had just happened to occur to her. She looked up at Elsa, whose face was frozen in a mask of terror. "Anna... your hand..."

Anna gets the idea to have Elsa magically reattach the pieces before unfreezing them, reasoning that if Elsa can create life, maybe she can restore it as well. Elsa does so, but can't make Anna's hand defrost due to being overwhelmed by guilt. Anna kisses Elsa full on the lips, which allows Elsa to unfreeze Anna's hand, which is restored to full working order. "See, everything's alright. There's nothing you can do to me that you can't also undo."

Over the next few weeks, Anna tries to get Elsa to freeze her again. They start playing around with this. Elsa also freezes Anna's clothes and breaks off the pieces as an alternative to stripping her the old-fashioned way. Anna is the one to start breaking off body parts on purpose, even using some of them as dildos with which to fuck Elsa. At some point she gives Elsa her frozen nipples and clit for safe keeping, saying that she doesn't want to come unless it's with Elsa.

Things escalate to the point where Elsa freezes and then slowly shatters Anna piece by piece until all that's left is her head and a pile of ice dust.

Trapped

(Skyrim, f/f, cannibalism)

On one of the previous incarnations of gurochan there was a thread in which the author wrote different scenarios set in the Skyrim universe in which dragonborn Lilith and her thane (bodyguard/servant) Lydia died in various ways. The following was one of my suggestions shortly before the author stopped writing. There's nothing specific tying it to Skyrim, so it can also just occur in a generic medieval setting.

While looting a mansion in the countryside whose owner is gone on a business trip for a few weeks, Lilith and Lydia inadvertently trap themselves in the wine cellar. With nothing else to do but wait for the owner's return to let them out, they start sharing stories. Inevitably the discussion turns towards their love life, and they reveal their affection for one another. Now they have two things they can do together to pass the time ;) After a week, however, the rations run out. When several days have gone by without the owner returning, Lydia offers herself up as a source of food to stave off starvation. Lilith refuses of course, but after a few more days of their growling stomachs keeping them awake, she finally gives in. They use the copious furniture in the wine cellar for firewood, both to cook the meat and to cauterize the wounds. When Lydia has been consumed entirely, Lilith has no choice but to start eating herself. When the owner returns, he finds two dead bodies in his ravaged wine cellar: one skeleton that has been pretty much picked clean and one limbless rotting corpse.

Grace's Anatomy

(f/ffff, vivisection)

It had seemed like such a noble idea: leaving her body to science. How was she to know that a few years later she would get into a car crash and that some idiot doctor who clearly had other things to do would pronounce her dead? Grace had sure given him a good scare when she came to a minute later. Unfortunately, the wording on the waiver she had signed was rather explicit: as soon as she was pronounced dead, her body would be given to science. Which was why she was now lying here, naked on an operating table surrounded by a bunch of first-year med students who clearly barely knew which end of the scalpel to hold. And these idiots were going to dissect her. She'd been given something to suppress the pain, at least, so hopefully their bungling wouldn't hurt too much. "Hey, girls, how about we get started?" she asked, startling the students, who were still discussing the type of cut they were going to use to open her up. "I haven't got all day, you know." The girls just gave her wide-eyed stares. "You know, because I'll be dead before it's over?" she tried to explain the joke. One of them giggled nervously. She sighed. This was going to be a long last day.

Extracurricular Activities

(Harry Potter, f/f, magic, non-lethal)

Setting: Harry Potter universe

As Luna Lovegood walked out of her last class for the day, she was approached by Hermione Granger. "Hey Luna, I found this spellbook in the school library. I tried to get Ginny to practice with me, but when she saw the title she refused, so I thought I'd ask you, since I know you're a little more open-minded." Luna looked at the book Hermione held out. "Natural Body Magic" it read on the cover. Luna shrugged. "Sure, why not?" After all, she didn't have anything planned for the evening anyway. They went to Hermione's room, where they locked the door and started reading, trying out all the spells on each other.

Obvious examples of spells include amputations, decapitations in which the head is still able to speak, complete vivisections (including heart, lungs, brains, etc.) leaving an empty torso, shrinking themselves to perform unbirthing or vore, destroying their bodies (e.g. by grinding them up or burning them) before restoring them and basically anything else that is physically impossible in more mundane settings.

Hazing Rituals

(f+, amp, non-lethal)

Setting: 'Car Fight' universe, in which advanced technology makes it possible to quickly heal from extreme trauma.

Alyssa is now old enough to go to college. She and several other female first-year students are put through a series of hazing rituals that involve disassembly.

The Hangover

(solo-f, scavenger hunt for body parts)

Setting: 'Car Fight' universe.

Alyssa blinked open her eyes, but quickly closed them again as the light was blinding, making her already throbbing headache even worse. What had happened? She tried to recall the previous night, but it was all a blur. She did remember that it had started out with alcohol. Lots and lots of alcohol. She tried to get up, but nothing happened. Carefully opening one eye, she looked down. She saw nothing. Further inspection revealed that everything below her neck was missing. Well, that was problematic. She looked around and noticed an arm and shoulder lying on the floor a short distance away. It kind of looked like hers, though she wasn't entirely certain. Still, it was better than nothing. Using her tongue to wiggle herself forward, she positioned her neck stump against the shoulder and waited for the two parts to join up. Now that she had a little more mobility it was time to find her other parts... and work out what exactly had happened the night before. (Cue glorified scavenger hunt all across campus, having to rely on vague accounts from other hungover party-goers such as "Dude, I think I saw a couple of the Kappa Zeta Mus use your pelvis as a frisbee").

Break a Leg

(ballerinas, f+, amp, non-lethal)

Ballerinas are known for being pretty thin in general, but the girls in Ms Morozov's ballet class are even thinner than most. For the girls, who are in their early twenties, know that their teacher has very strict physical requirements for playing the lead role in their upcoming rendition of Giselle, so they strain their bodies to - and sometimes beyond - the limit. Last week, for example, Olga did the splits quite literally when her legs came off entirely. But as they say in show business: the show must go on, so the students keep dancing, despite their missing limbs, competing with each other in an effort to land that coveted part.