An adorable old man that entertains kids with old histories of heroes. But behind that appearance lies a powerful wizard with a hard mission.
A beautiful girl, queen of a small kingdom. She is the last descendent of the Great Tempest, the choosen of Hydros.
Animals have parasites and diseases, so do plants, there are even bacteria that cann dissolve oil spills or plastic or what have you - why couldn't there be a disease living off magic - a magic item could be infected, losing power and speading the plague to other equipment it contacts, while a magic user would slowly lose his powers and contaminate all he works with or casts a spell at...