Disclaimer - I've only seen the Mystra interactions on youtube and I don't have Gale in my party but it seems the game has introduced a third weave. Which is pretty interesting - it makes sense that Karsus' folly would form a new, corrupt weave. And Mystra seems like the best entity to control the crown - she would best know how to destroy it. You wouldn't want a product of a corrupted weave to be out there in the world . . .
The only deity that could possibly be better would be AO but AO had the tablets of fate stolen from him so it's not like his vault is impenetrable.
