Oooh, there are some good ideas here, thanks. I think I'll point our new GM at this thread, in case he wants to bring other Greek Pantheon sponsored NPCs into the game.
I feel like my current version of Athenian/Hermesian sponsored magic is kind of an anti-climax at this point.
First, they want him to be a good messenger and herald of their ideas, so we start off with an item of power, based on Hermes's wings, that grants inhuman speed and a little protection.
Second, he still has to get places quick, so Sponsored Magic allows him to perform rituals to open passages to the Nevernever, and even do so with evocation's methods and speed. He can also do a little bit of communication related ritual magic, mostly divination and reverse divination for sending messages.
Third, most of his evocations center around the ideal of the hero. I'm sure Athena would prefer more references from traditional Greek myths, but she's read The Hero With 1000 Faces, so she's ok with the fact that most of her champion's evocations involve stealing the shticks of Marvel Comics Superheroes. Magic is all about belief, and he believes in Wolverine, The Hulk, and Nightcrawler, in addition to the Greek Gods. Also Jedi.
So far my guideline is that most of his evocation magic should look like Spirit Evocations, or tricks with gates to the Nevernever. Spirit is pure force, so I've got a good bit of leeway with that, but I'd like to refine the list of possibilities and restrictions a bit. I'd also like to get a better handle on what does and doesn't belong on the list of reasonable rituals.
Removing summoning and binding sounds right, transformations that make someone faster or more persuasive should probably be in. Wards yes, but maybe with some restrictions? Just brainstorming here. Thanks for the suggestions so far, hope I get to hear a few more.