I can only assume that this is a glitch due to how it works, but correct me if I'm wrong.
Upon electrifying a pool of blood created by the witchcraft skill bloodletting (possibly any blood source), while it is also touching water (may not be important) will cause it to rapidly expand to a ridiculous degree. An entire battlefield (and then some) can be covered in blood with just three spells. This also ends up making it extremely easy to shock entire packs of enemies permanently by using blitz bolt.
