Yep... I'm writing one of these... Trapped in that locker, Taylor Hebert triggers, and gets all the powers of the Queen of Blades. Too bad half the school sees it happen. So much for a secret identity. Disclaimer: This was a rush job. (Feel free to steal any of the ideas here-in.)
Whateley Universe. The origin story of Rouse. Mutant powers are funny things. Sometimes they're awesome. Sometimes they suck beyond reckoning. Cameron Endel was one of the lucky ones, but even with fun powers, one can still end up in the wrong place at the wrong time, and lose everything. And yes, there is plenty of Gender Bending along the way.
Xander, Dawn, and Tara do Corruption of Champions. Trapped in Mareth, a hell dimension of supernatural lust and carnal depredation, Xander, Dawn, and Tara must make their way in the conflict between demons and the land itself... without being transformed into something else entirely. (Rated M for kinky weirdness and non-con.)
Worm fusion. Four teens make up the supervillain gang known as the Undersiders, but in this AU, those four teens are Willow, Xander, Cordelia, and Oz. Taylor Hebert with a different power joins up, and dastardly deeds ensue. UP FOR ADOPTION.
Because it had to happen eventually. Shameless self-inserts. Into Worm!
Ginny Weasley pulls a PeggySue after Harry dies in the final battle. Featuring a determinator!Ginny who doesn't care how the previous timeline went, she's going to save Harry no matter what. Also, a minor not-really but sort-of crossover.
Nineteen-year-old Albus Potter finds himself bound to eldritch abomination Minnav'ahk'rallhn in a twisted take on the MagicalGirlfriend trope, while his older brother James is - DOING NOTHING SUSPICIOUS. AT ALL.