Appealing to his lack of appearances isn't really arguing against his power. It's just a point that has very little to do with the outcome.
He was toying with an amped Apollo, and while we never saw even a fraction of the supposed thousands of powers he had, we saw enough to know that this isn't a cakewalk either way.
As with most characters with few appearances, anyone's opinion is somewhat speculation. I'd lean toward Seth, but it's hard to say that with any amount of certainty. Either opinion could be right, because we just don't know enough.
