Ice Element ideas

The ice element is a definetely underpowered in comparison to all the others.
The frost crescent enchantment needs better scaling, since it has the lowest of all elemental crescent effects, while not having a DOT like fire or poison. 
An increase from 20% to 30-40% would be a lot better unless an additional effect was added to the frost debuff. 
Some possible additional effects (along with the slow) could be:
Getting temporary HP for every enemy hit by frost, making it a defensive element for tank builds and a counterpart to lightning (One make the enemies weaker, the other makes you tougher)
Enemies that are affected by frost explode into ice shard when defeated, dealing damage equal to their max HP
Enemies affected by frost are also "Brittle", making them take more damage from critical hits (this could also apply to the player, taking critical damage from a percentage of enemy attacks)