An idea Gold and I came up with. xD
Basically, we had the idea that some fae still exist among Serenians and blend in with people, and some (such as the unseelie, or malicious fae) are trying to take back what was first theirs. Some do it by contributing to the cults, others try and work from the inside.
Changelings could be a problem in Serendipity, with Serenian children being swapped with fae children, and the Serenian children are then raised by the fae and turned against the Serenians. x3
Just some ponderings! 8D