Neutral creatures

Water elementals have a shield that returns a portion of the damage and an ice arrow that freezes the target. It's a shame that the arrow was nerfed in version 1.2.
Light elementals have a counterattack that is represented by an 8-pointed star, which deals damage to all enemies hit by the rays and heals allied units that are hit by the rays. They also return a certain percentage of the damage received.
Dark elementals could remove positive spells from enemy units, similar to the "Radiance" spell.