I ran into the same issue you guys had with Mage in Arena >< granted I only played 3 at the time instead of 4, but Ice Block wasn't even an option unless you went Frost. Overall it felt clunky and as mentioned a lot of their abilities that make them viable in an arena setting just can't be fully utilized when multiboxing. If Water Ele Freeze could be more streamlined in that you could use your main to somehow target your secondary characters Freeze, it would be insanely awesome. Just set it in rotation easy dead targets.