Thinking about it now though, in light of your points Wilshire, I had thought it almost certain that they would hide.
However, thinking back, doesn't Aurang show up himself? Like, as in, not the Sythese?
Two things are possible here, either Aurang felt that the goad had to be good enough (I think that he was trying to lure Kellhus away from the Nuke, so it would catch more sorcerers) or it was a ruse, some sorcery he knows to only make it look like it was himself in person. Not sure which is more probable. I am thinking though it was not actually him, or if it was he had some kind of "fool proof" escape plan.
It's also curious that Kellhus didn't just teleport to him and kill he straight away...perhaps he knew it was a trap?