That is a major character that has been teased and will be introduced next episode.

As you said, the first season had some incredible moments but was overall pretty forgettable. I don't think I even bothered to watch the finale. That said, I am really loving this season and find it far more consistently great (although some missteps here and there). The show just does crazy ambitious stuff like…

Well to be fair, she is a two game winner who should have a huge target on her back, and she has gone to tribal 4 times in 5 (!!) episodes and not received a single (!!) vote.