Pandemonium casting delay sucks, this isn't a targeted or definitive spell (random effect) so it should be instant. 

Bug - can not cast Chaos against an enemy that already has a chaos driven effect on it (i.e. slow from initial casting) to see if you can get a 2nd one or a damage outcome.

suggestion - Elementals suck - they need more special attacks/spells they can cast that are of a matching type, IE. fire elemental gets flame dart, ice elemental gets ice shard, air elemental gets to blow me etc...