Matter and energy are different forms of the same thing. Any supernatural power would still be a form of energy, though perhaps in a form we may not recognize, or subject to additional contextual stimuli we may not be capable of percieving. As such, I guess I'm probably a materialist, as I would believe anything, including God himself, if such exists, to be comprised of matter or energy of some form or another.
I also believe that the mind, is a combonation of latent DNA, pre-made cellular structures, chemical balances, and growth of neurons from experience. All of these aspects are physical in nature and are fully capable of explaining every aspect of the mind including the soul, though I do still hold a theory on the concept of a spiritual energy source which we just haven't been able to identify / measure yet, similar to gravity, that too would likely be a form of matter.
Then again... gravity gives me pause. It generates an infinite amount of energy as it never diminishes with time, and no physical aspect of the matter is reduced in its' process of creating a gravitational field. We can't find any evidence that there's any kind of field or wave as such, nor anything even remotely resembling energy... yet it clearly exists. As it is infinite in its' creation of gravity, one may surmise that it may not actually exist as a form of matter nor energy...
That fact gives me far more pause than the concept of god or thought, souls, or anything else.