Creating a good illusion was impossible for the low rank fiends. However, creating a perception wall on something to make it practically invisible to the human eye was easier. Though fiends too were like humans in ability wise, they were completely random and mostly unique.
Some low-ranking fiends could possess illusion abilities but lacked the intelligence and knowledge to use them effectively, while others might have mind-altering abilities that didn't require intelligence to use.
Auriel guessed that the fiend in question had the power to manipulate perception by creating walls around objects or locations, like the house they were investigating.
As an Awakened, Auriel's heightened senses allowed him to sense that something was amiss with the house, he just didn't know what.
