The one drawback to Wicca is the Pacifist Quirk. Most gamers howl when they lose ‘specifically offensive’ spells. When they call down a bird strike or a landslide, they have to give baddies a way out.
To head off this discussion, neither the two classes from D&D, monk and mystic, fit. And the psionics rules from AD&D need more work than I’ve seen fit to give them.
Magus, dabbler in the occult arts, will suit the milieu better. As in the real world Dr. John Dee. An excellent delineation of this is in the first few seasons of Supernatural.
The Perk would be Arcane Knowledge (occult) 2
Mythopoetic Games covers this at length in Danse Macabre. The powers will have to be scaled back.