with every elemental crystal u get ur power over that element gets stronger.it also would make your pets stronger.once u get enough u should get another spell in your element.for example earth u could get stone throw. you throw stones really fast and rapidly. u could gain this spell and keep the other one too.

a box that explodes in a set of spells(the spells depend on where it is)

what about you can upgrade your stats by finding items and stuff