One of the main reasons The Iratus are so feared is due to the experimentation that they are known for doing on other species'.
They are incredibly curious by nature, wanting to know as much as possible about any living being. They are willing to do whatever it takes to get the information they need, and psychological experimentation on unwilling participants is commonplace.
The minds of The Iratus themselves are incredibly resilient, so a main interest is how other species' are so susceptible to being driven to the brink of insanity. It is a common reoccurring theme throughout the World of Immensum.