The Sun People
The Sun People are a religious minority who practise an offshoot faith stemming from the Church of Fire. Expelled from the Fire Nation for their heretical views, they now reside in Sun's Hearth in the Air Nation.
Beliefs
The initial heresy of the Sun People against the Church of Fire was in the rejection of the supremacy of the Book of Fire, which among other things, stated a requirement for believers to profess absolute loyalty to the Firelord. This authority was disputed by the Magus, who argued that the firebenders' way of life was to be intrinsically nomadic, akin to a bushfire that moves over plains, and thus any religious authority rooted in the site of a castle city could not be said to have any respect for the sun. The Magus preached an alternative form of the ideals of the Church, with notable differences including but not limited to the Allfather accepting sacrifices, referring to the Allfather as simply "the Sun" despite seeing the two terms as functionally identical, the need for consistent motion, and a rejection for "stonelike" society.
Practices
Little is known of the Sun People's religious practises prior to their exile from the Fire Nation. In the Air Nation, much was observed by local Empyrean observers. The Sun People would commit to weekly gatherings at the mound of Sun's Hearth, offering contributions to the Sun and praying aloud through ceremonies led by the Magus. The Magus held a great deal of non-spiritual authority in the community, acting as the locus for all negotiations with the government and their airbending neighbours.
Scriptures
Due to their disavowal of the Book of Fire, no formal scriptures exist for the Sun People's faith. All spiritual matters are designated to the authority of the Magus, whose opinions are not recorded in text. Consistent trends, however, do exist. The Sun is expressed as the direct object of worship, with weekly sacrifices offered in its name, and treated as a god unto itself. Emphasis on the nomadic nature of fire, holding no firm edges and constantly in motion, is also a consistent theme.
History
The heretical beliefs of the Sun People soon earned the ire of their neighbouring Flametouched within the Fire Nation, prompting immediate attacks and violence endorsed by the Firelord's government. True to their nomadic beliefs, the Magus led his people into exile and soon entered the Air Nation to form the community of Sun's Hearth from land allotted to them by the Elysian Templemaster.
While in the Air Nation, the practise of offering sacrifices was condemned harshly by their Empyrean neighbours, causing terror incidents to break out. Violence was extremely common for a time between the community and its neighbours, only abating with the creation of the Western Temple. This far-off temple's creation saw the Elysian Temple lose territory, which was compensated through the annexation of Sun's Hearth. With this change, as well as the promotion of non-airbending Empyreans such as Guru Ed, the incentives for conversion among the Sun People became far stronger. This was briefly interrupted with the arrival of the Toshkii, whose indigenous religion of the Cult of the Mountain became a temporary counterweight to Empyreanism, causing some to convert to the cult out of resentment for local Empyrean oppression. With the thorough dismantling of Toshkii power and their integration to Empyrean society, this too ended.