Challenge Idea: An Angel Named Fitch

I realise I'm not supposed to make challenges in the official story category but there are nothing but RP forums on site and I would really love to see someone take this idea and run with it. I mean really, where are the ones to post challenges to? Anyway, This is a Supernatural/Once Upon A Time crossover challenge which can either star our favorite blue eyed angel, Castiel, or another angel you pick/create. Castiel would be preferable but that's just because he's adorable!

Before I give the premise away I have one condition. No slash/yuri unless it is canon. I say this because there is enough slash in the Supernatural fandom already and I would really just appreciate a good canon relationship fanfic. (Besides I think Dean views Cass as both a friend and a little brother most times) Really I feel like I'm drowning in the slash everytime I look for something interesting to read.

So, here's the premise if you guys pick Castiel as your muse. This is set after Dean gets out of Purgatory and sometime after Rumple starts looking for portal magic to find his son, because time is decidedly wonky.

Castiel found his way out of Purgatory, but the exit led to the Enchanted Forest centuries before the magical curse would rip the fairytale characters out of their world and into his own. He is soon captured by Chernobog and held prisoner until Rumpelstiltskin, the new Dark One, discovers him while looking for information on portal spells and steals the angel's memories. With his new identity of being Fitch, Rumpelstiltskin's messenger, replacing his life can Castiel's old self be recovered when the brothers Winchester roll into Storybrooke?

The premise for using a different Angel as a muse is much the same though you can tweak it to take place at a different time for Supernatural, such as before the show or whenever during.

The name Fitch comes from the Grimm Tales, Fitcher's Bird, which stars neither a bird nor a man named Fitcher but does have an evil sorcerer whom likes to steal marriageable girls, give them a test, and then chop them up when they fail said test. (Sounds like something Rumple would do.)

Anyway, now it's time for what I would like to see out of this story. Winged!Cas, because that would just fit so well, however, the spell that keeps his wings manifested should be a complicated bit of magic that was cast by Chernobog whom was stealing Cass' feathers for spells. I figure this way sets the story up for more problems that need solving. With Cas having false memories that also makes the story ripe for some fix-it moments especially when he starts to feel conflicted due to the history he has serving his master the Dark One.

I don't care how many of you take this challenge up, I just don't have the patience or discipline to write this and I'm not that far into either show myself (a lot has been spoiled for me) so yeah, I ain't got the credentials for this. Plus I don't have the frame of mind to really do characterizations of Dean justice but I really want to see a good SPN/Once crossover, there aren't enough of them, (like two worth reading) so have at it and have fun!