Erupt
I think it could use more damage power, for 500g for the skill i feel unsatisfaied. Or change talent in mage tree if i remeber well 35% for smoldering caldera for 2 talents points. I can't understand why most of aoe (area of effect) spell/skill are also dot's (damage over time). Dragon breath, blizzard, frost spikes, engulf, whirlwind, that poison attack from assasin why all are dot's? From not the dot's spell: frostbite, meteroite or erupt (mixed here). That arent that effective, but got their cons.
I don't know about the lvl 50 spell for mage, cast instant, but to be honest getting an aoe on end game, what the use to farm with aoe then? So maybe change those skill to lvl 45?
So i want to suggest increase the power of aoe's or lower it but make it instant not over time or increase it cooldown to avoid the same thing with frozen spikes nerf.
Peace