[Thaumatology] Divination as the Core of Magic

[dataweaver]

I'd be wary of the Insubstantial one, because it isn't just about not getting hit; there's the whole “I can't affect anything that's not also Insubstantial” thing going on. And the +100% Affects Substantial enhancement doesn't actually let you affect substantial things on its own; it merely gives you permission to buy and use abilities that do. Even with severe limitations on it, the result is unlikely to be cost-effective.

Other than that, this looks pretty solid. The only thing I'd add is that you might want to look at the optional rules for Spirit powers found in GURPS Powers — not because this is a spiritual power, but because those modifiers are designed with the sort of feel that a GURPS Horror “mancy” ought to have. I'm referring specifically to the Ritual Modifiers found on Powers page 178: Affecting Others, Consecration, Regalia, and Ritual Length.