Specifically the 10th level feature Alter Reality.
Alter Reality (Sp): At 10th level, a thrall of Fraz-Urb'luu gains the ability to transform an illusion spell into reality, once per day. This duplicates the effects of a wish spell, save that it cannot grant inherent bonuses to ability score or duplicate any spell of 8th level or higher. The reality to be created must first be manifested with an illusion spell of at least 3rd level before this ability can be used.
Even 1/day this seem unimaginably strong because with say Mirage Arcana or Major image I could create ANYTHING the illusion could simulate, and there is no duration which makes it even more broken. Am I missing something or misinterpreting it or is this really as strong as I think it is.