drallinix said
He created the wall inside the flames at the entrance of the cave. The flames had already entered somewhat and he made the wall inside them to conceal it.
My point is that erecting the wall would prevent any further flames from entering, making it obvious that the wall was there. Not to mention the fact that his counter-attack would hit the wall and get stopped, giving yet another indication that it was there, and he wouldn't even rush toward the wolfman in the first place, since the action preceding that was interrupted.
I just wanted to be clear on the positioning of the wall.
Edit: Regarding Ug Nug, Arthur hasn't even made it out of the cave to where he can see him yet, though he was apparently standing closer than I thought when he first showed up. I also didn't realize that your post about not interfering without an invitation was a request for one, but I'm fine with you joining if you want and the others have no objections.
Edit to the edit: A cave in would only slow the fight down, and I doubt that hitting the cave wall with a club would produce one on the scale required to have any significant effect on the fight, considering that it just withstood two hurricane force wind blasts.