Barricades
Leonel had recently stepped into the Third Awakening of his Wisdom Branch. Unfortunately, it didn't give him the boost to his mind that he had hoped for. But, what it did do was give him a sharper pair of eyes, eyes that could see much further within this fog than his Internal Sight could.
From just a few meters, Leonel's line of sight extended to about 50, allowing him to see what was going on.
There had been many cabins much closer to the black log wall, and many of them were geniuses on a level beyond those still struggling to get past the wall of fire. So, they had been able to clear the walls alone without relying on the tricks that Leonel had. They were likely talents that had either earned Golden Tokens or had been very close to doing so.