I do dabble in other fandoms, mostly by request, but occasionally something leaps fully formed out of my skull. Not all of these are anime fandoms, I note.
I hope you enjoy these with your brain!
Elisabeth (Takarazuka show)
Full Metal Alchemist
The Family Cactus, in which the King shares some family history with the Prince
Persona 3 (Shin Megami Tensei series)
Fairy Chess, in which I demonstrate that Lucretia Merces is a strategist in every aspect of her life (written for Yuletide 2008)