Seeing as how i'm using this in EtA, i figured i'd post it.
ASTROMANCY [-4]
Description: You wield power over the physical and mythological aspects of the Sun and the Moon. This power is generally wielded by priests, witches, and druids.
Sponsor: This power is often self sponsored, gained by heliomancers and menemancers who learn to blend the two arts. However, gods of Day and Night will often grant this power to their followers. If so, it is sponsored by them. Amaterasu, Tsukuyomi-no-mikoto, Apollo, Selune, Helios, Artemis, Horus, Ra, Quetzalcoatl, Svarog, Nut, Sekhmet, Hecate, and Chang’e are all gods or goddesses whose portfolios include the sun or the moon, and thus are capable of granting this power.
Agenda: The preservation of the balance between Day and Night. Protection of both the Sun and the Moon against creatures who would do harm to either, such as vampires who want the sun to go out, Summerfae who would love daylight everlasting, and so on. If granted by a god, that god’s agenda.
Evocation:You can manipulate aspects of the sun and the moon. From the moon, you gain power over darkness, cold, gravity, earth, oceans, blood, time, trickery, and madness. From the sun, you gain power over light, fire, electromagnetism, nuclear forces, radiation, space, growth, battle, and plants.
Thaumaturgy: Rituals cast with Astromancy make use of the same themes as Evocation cast with it, but their applications lean towards the abilities of deities of the day, the night, and the sun and the moon.
Evothaum: Any ritual that can be cast with Astromancy can be cast with evocation’s speed and methods.
Extra Benefits: The power granted by the sun and the moon changes depending on which one of those is in the sky at the moment. During the day, you gain the Sight. During the night, you gain Cloak of Shadows.
The extremely broad evocation elements are where people might take issue, but that's honestly a flavor thing. Trapping someone in a recursive space loop (Block vs Conviction/Alertness/Lore) isn't much different than imposing your will on someone's motor centers via Spirit evocation (Block vs Conviction/Discipline/Might). They're also fairly accurate representations of the portfolios of the gods mentioned above.