Mana Hounds

 (Image by Pavel Balabanov) 

Whether some foul magics, eldritch contract with some outer world being or a curse laid upon by the gods, none know, but it is known when.

No reference of the Mana Hound exist before the Battle of Broken Crowns, and the coming of the Crystals. What connection these have with them isn't known, but what is known is that the protective field surrounding the Crystals prevent the Hound from entering, and that is enough for most people.

Casters outside the protection of a Crystal, be wary when wielding your magical arts, for when a Hound gets your scent, they are near impossible to lose.