Decided to share some monster creation experience. These "Shattered Gates" threads will be eventually moved to other forum topic. What is interesting about Grimlocks, that they are completely blind, and have vast visual immunities, and their blindsight range is 40. Blindsight is feat introduced by @_doug_ in this source file scout.py. But I'd assigned first argument as range specifier, what do you say @_doug_ ? Although it works nicely with Concealment condition. The Invisibility would make AI to ignore PC. Which is fine, I guess. Gaze Attacks. I think no PC abilities or spells are suitable for this, so skip. Illusions. That one is straightforward to implement. I have created new condition immunity_illusion.py. It is based on Spell school, if D20STD_F_SPELL_SCHOOL_ILLUSION then disallow. Visual Effects. This one is a bit difficult, as there are is no either visual school, or even visual descriptor. But, if one look into the Flare spell, it has descriptor of Light. So I decided to use this as prerequisite for spell immunity dismissal. See this file - immunity_visual.py. Unfortunately not all visual effect spells has this descriptor. So I decided to modify at least one - Glitterdust. This one should not work, so Light descriptor was added. Perhaps more to come.