I'm looking at the stated mechanics behind the power.
That isn't mechanics, it's fluff. There are no rules associated with it.
Speaking of the point cost, how many positive refresh is Divine Purpose worth?
0. It's just a guide to compels. Compels are not bad.
It is what it is. It's in the book, it's RAW. You don't have to like it, but if the RAW drum gets beat, it gets beat for those, too.
I know.
See, I don't particularly like the Warden Sword. But I understand the reason for the way it was made, I think. (And no, it's not overpowered to balance out the job requirements. Harry has those with no Sword.)
Let me quote myself ranting about narrative mechanics:
If you assign a mechanical value to a narrative decision, then everyone ought to make that decision. So you don't do that, ever, unless you're trying to force people in a certain direction for some reason.
The Warden Sword is probably the way it is in order to push people in the direction of being a sword-swinging Warden. It kind of has to be overpowered to do so, because taking Weapons on a character with Evocation is not a great idea.
If you take it as a precedent, then the whole thing collapses. Which is part of why I dislike the thing.