Hmm, one problem I have with most of the suggestions so far (including mine, which is currently leading in the poll) is that this seems to be a villain
trope, while antagonist doesn't necessarily imply villain any more than protagonist implies here.
I admit to occasional lumper tendencies, but I think we may be in danger of lumping too much into this one if we go with any of these names.
eta: Main Villain
sounds too much like the Big Bad
, so I'm not entirely sure what to suggest.
edited 7th Feb '13 2:54:42 PM by Xtifr
"Existential Despair" is an oxymoron.