Board Thread:General Discussion/@comment-34924658-20180208001617/@comment-5899967-20180208122318

I still think it was Fiona, as she was the creator of the curse, there was a build up at the final battle since the pilot, and so it connected the first 6 seasons. Plus, Gideon as a bonus because he's Rumple's son, one of the major big bads of the show. And obviously the Evil Queen in season 6, since she was the main villain in the first season. So all 3, Evil Queen, Gideon, but especially the Black Fairy.

Season 7 is a different thing, so there is no ultimate big bad climax or build up.