So i lost the link to this fic! I read it awhile ago but basically it was a Supernatural AU! set in in an AU version of Heaven where Chuck is marrying a Demon princess who brings an honor guard with her (including Sam and Dean). Gabe and Cas are part of an Elite group of Angels that guard the palace. Slash happens. It was a big bang piece i think if that helps any. I would love to be able to find it!