Rare Abyss Mob Modifiers? Unkillable Rares?

Does anyone know where I can find a list of all the Rare Abyss Monster modifiers, or can tell me what some of them do? I have a "Crystalline Barrier" and "Amanamu's Void" serpent guy, and I cannot damage it... I have no idea why, and I can't find information anywhere. I think it's the Amanamu Lich mod but WTF am I supposed to do?