As far as I know he's been reported as being the villain in press, but because I think still who he is has never been announced yet that word 'may' be imprecise. He appears to be the antagonist as things stand at any rate.
I don't think anything is really confirmed yet.
'If the Apocalypse starts, beep me!' - Buffy Summers
'The sky's the limit.....' Jean-Luc Picard, 'All Good Things'
courtesy of Saquist