sb_fag_ends is going for the win for Halloween.
Pick a side, any side. Hell, play all sides and see where that gets you. And fanwork like you wouldn't believe. Support the DARK SIDE, the FIERY SIDE or the SIDE OF PEACE AND NATURE, and pretend we're not friends with all three :-).
Seriously, look at the amazing prompts and write for someone, anyone. The spell ingredients (some obscure) give you a whole raft of potential prompts.
I'm off to toss a series of coins and pick my contender. Be warned, I'm feeling peaceable though...
ETA Yep. I am team Vivia. You who want to create dark, skeletal or hot, dragonsome fanworks are my sworn enemies for the next nine days. Yus. Also, I am totes in the market for an ally who can do fanmixes about deer antlers, because I CANNOT and WE CANNOT WIN without although we are then deepest rivals for the Grand Prize. Hey! Wanna team up and be awesome? (There are probably many other things on the list I cannot do and need awesome allies for, but this one is already LOOMING at me after some browsing.)
LOOM.