As you explore Andrus you may notice the lack of details on faith and deities throughout the setting material.
Faith in role-playing games is nearly always a rehash of familiar, real-world pantheons and powers. The cosmic conflicts deities bring to a setting can be formative, but they also come with the danger of not being overly unique. World creators are often limited in their perception of faith and divinity by the influence of personal beliefs, real history and previously published materials.
In Andrus faith is more a storytelling hook than mechanic. It is not specifically tied to magic or healing or turning away dark powers. I envision Andrus as a setting where a character’s personal convictions and cultural values are the driving factor, not the power of belief in a deity or pantheon. There are powers at work that could be construed as ‘deities’ but that’s because of their level of power relative to the rest of the setting. The Medusa and Naga were effectively the top of the food chain in power for a very long time. That has started to wane with the defeat of the Naga and the reclusive nature of the Medusa. Even the nebulous power behind the Sepulcher Throne, the Shadow, is intentionally beyond most mortal comprehension for story purposes.
A player can absolutely tell a story of faith through their character, but it isn’t specifically reflected through game mechanics. Access to any of the Magic related Traits could easily be justified by a player’s application of faith but that is not the default interpretation for this setting.
Faith is often tied to a culture’s perception of creation, morality and an attempt to explain the great ‘why’ of existence. Deities are essentially elevated vessels for ideals, a personification of frightening or awe-inspiring phenomena and paragons for cultural norms. Positive ideals are worshiped while undesirable ideals are vilified. It’s often the interpretation of what is positive, ‘good’, or undesirable, ‘evil’, that causes friction between cultures.
The concepts represented by primal deities are typically physical, moral or natural. These concepts do not really require a name because every culture can recognize their power and influence.
Below is a basic list of some of the most common influences for deities. This is not a comprehensive list, just a starting point. There is no designation of ‘good’ or ‘evil’ leaving that to each culture’s interpretation.