Besides understanding that different origin race members followed different sealing methods for elemental planes, Walker was in awe of the complexity of those runes used.
They weren't turn formations that someone crafted to follow a specific pattern. They were naturally formed runes condensed by someone with power to condense them naturally.
Simply put, making a naturally occurring rune with mana manipulation is an incredible accomplishment. For Walker, it could be considered impossible still since he couldn't condense this mana in this quantity.
The condensed fire runes and earth turns showed him a density that supported the manas mixing within this elemental plane. It also showed the level of strength needed to condense this elemental plane was at the level of potentially being able to spread their mana sense a hundred times larger than what Walker knew he could right now.
