I gotta put my vote on Q.
For the prophets to do anything to you, you need to be in their world/inside the wormhole. While Q could simply just make the prophets disappear, nomatter where in time or spacer he may be.
However if inside the wormhole, I think it would be the fastest-on-the-tricker concept, that would decide who'd win.
I've always wondered what would happen if one Q made another Q disappear forever. Would that other Q instantly counteract the attack, or would he just disappear!? I mean, the Q seen in Voyager, who wanted to kill himself, was "imprisoned" by the other Qs, however could not kill himself nomatter what he tried, and it seems that it takes the Continuum to make a Q mortal... Though in TNG in one episode, Q gives Riker the power of Q (he makes him a Q), but then takes the powers away again, when Riker refuses to keep them.
... sorry, this has become an intirely other disgussion, however still somewhat relevant to the subject, if you ask me