Rain gulped when he understood the true power of the dungeons… they were able to gather mana from the dead of those who had the blood that created the spell of their formation. Still, they also absorbed the mana used inside it… and that energy was probably being used to change the interior of the dungeon. That would explain the cold, heat, and dust.
"... Wait, how is that possible?" Terra asked. "Are you saying that the dungeons are a spell able to drain the mana from the environment to enhance itself?"
"It most likely is. There is also a chance that it can also absorb the stamina that we use there. I will have to make some more experiments to confirm that," Rain explained.
