User blog comment:Domine./Morgana's torturer... Hypothesis./@comment-4475616-20120720222718

I don't think it's an character we already know. Katie said in one of the interviews, it'll be a character we get to know later in the series. That eliminates basically anyone we already know, at least the ones we already saw on the show.

I'd say it's someone who was mentioned already, but never had a part yet, like... King Lot! Yep, that's my guess! :D He's been hinted at in the last series, and I think he'll play a role in series 5.

Or maybe it's King Rodor...