The style I have been developing is meant to be effortless and instantaneous (within yourself, you have nigh-omnipotency, so why should your powers take time and effort?). It relies primarily on channeling, though not necessarily by channeling energy through one's own body. Usually, a coven of low level "white witches" will consist of a mix of "vampires" (who naturally drain energies of those around them) and "batteries" (for lack of a better term) (who naturally bleed excess energies). You can identify them, even without psychic sensitivity, because they call themselves Wiccans and (neo-)Druids. To neutralize such a coven, all that is necessary is to move their energies around in their circle. When they join hands and form their circle, they are at their most powerful state, but they are also at their most vulnerabe state. The vampires will drain the batteries in excess. The vampires will be overloaded with energy, and will be too jittery to concentrate or move effectively. The batteries will be drained and completely incapacitated (i.e., lying on the ground). In other words, I vehemently agree that you should "use theirs to destroy their own." I use no shields, and fear no direct attack, for I have not yet met with a formidable coven.