As an ST one of my players healed a message raven that was going to die of exhaustion. The life of a single bird was not that pivotal to the story; but it set up his compassion and *flex* AWESOMENESS *flex* so I allowed it. I feel it really is a charm that is dependent on the situation, being a charisma+presence thing.

I think I would allow turning water into wine. And bread into fish. Quell a raging storm. Walk on water (but not during combat). Standard stuff for the exalted ...