I'm not sure if this is a bug or something not implemented in the Ai, so I'm just going to put this in Suggestions.
Gremlin Mages are able to cast some sort of a protective "bubble". The AI of the Mages does not seem to actually keep the mages in that bubble though. They cast it, stand in it, spot you getting nearer and flee as they usually do. Why the need to flee? They're in a protective bubble afterall, out of which they get free shots at us even more.
If we're going to have them stay in their bubbles, then they need to switch the bubbles to being objects instead of being "alive".
To clarify; These bubbles are HEALED by the Heal Auras the Mages can place. I've had a situation where I brought down two of three mages, the third bubbled himself, put a heal aura up, which prevented my partner and myself from breaking through his shield before he could cast raise dead on the other two mages from the safety of his bubble.
Shields should not be healable.
Is there even any point in trying to break shields most of the time? From what I've seen, they have enough health that it's not much slower to just let them expire.
I'd like to see a casting time on this spell while we're at it. Mages seem to cast it when they get low on HP... including halfway through a charged attack from a vile striker. The entire charged attack lasts 3-5 seconds, and critical damage comes after 2-3 swings- so this puts the response time at near-instantaneous. It's kind of frustrating to kill an enemy that might become invincible as soon as you hit it.
Also, although making the dome breakable was a really nice bit of balance, healers still retain an awful lot of power while in the dome: they can heal themselves or others, prep attacks, etc as they choose. Could the dome spell be modified to impose more limitations on the caster while active?