After checking with the QA team about what you’ve described, they were curious if in this case the opponent had activated any effects that could have caused Darigaaz to gain the “Knight” subtype. Do you know if this could be the case? In addition, do you happen to have a screenshot of what you saw going on when you noticed this happen?
@Tombstone this bug has been there since DOM came out. Aryel does NOT check creature type for her abilities. It just disables the creature with the highest power