Throughout the dinner, Dexter willingly informed Aries of the general details of the relationship between vampires and witches. From the information she had collected, witches and vampires apparently had the same origins. Although witches and warlocks such as Isaiah were biologically human, they weren't livestock, vampires would want to devour.
Dexter didn't clarify anything regarding Aries's gift or curse, but he asserted it was a dangerous power to wield. Unlike vampires — turned ones, in particular — who had to sacrifice their means of survival by drinking blood, witches make more sacrifices in each powerful spell they cast.
Each spell, especially ancient and black magic, could harm even its own caster.
