Dortheiga, Nanumia, and the 300-year cycle
Although Dortheiga and Nanumia are considered polar opposites by their followers, the defining trait that separates them from ordinary Dor users is the same. Both Dortheiga and Nanumia are self-springs, people who can generate Dor as if a wellspring traveled with them, as opposed to ordinary Dor users who can only channel and manipulate ambient Dor of a type they are attuned to. Prior to the events which solidified hostilities between Dortheiga and Nanumia, self-springs were rare, but random, occurring at any time and any point on the color spectrum. Today, the only self-springs are Dortheiga and Nanumia. They appear in 300-year cycles, one Dortheig and two Nanumia exactly to each island. If a Nanumi or Dortheig dies before their first birthday, another eligible newborn takes on the role; otherwise, once a Nanumi or Dortheig is killed, there will not be another in their role until the next cycle.
Exactly what the cycles are and how they happened is unclear; many stories exist, but all have been distorted by the conflict. We know that there are many pre-conflict stories of self-spring warriors and heroes who became great leaders in their communities, and that the Dortheig lineages have their origins in powerful families who produced self-springs more often intermarrying to strengthen their bloodlines. We also know that these Dortheig lineages ruled without opposition for some time before the rise of the Nanumia. We have absolutely no idea what actually brought the initial Nanumi rebellion about; Dortheig supporters claim it was a simple, baseless attempt to steal titles and power, while Nanumi supporters list crimes so numerous and horrific that if all of them had actually occurred it is unlikely the islands would still have a human population left. At some point during the initial conflict, Dor users including self-springs on all inhabited islands did some massive and complicated coordinated spellwork. One of these massive workings was created by the Dortheig supporters, one by the Nanumia. The exact intended nature of these workings are also mysterious, though they were likely some combination of attack and counterattack. Stories on both sides claim that oaths were involved somehow, which is highly unusual for Dor spellwork. The two workings happened to activate at the same time, became tangled in each other, and reacted violently; when the dust had settled, one massive working made up of component parts from the two originals was running through the archipelago in patterns still not understood by modern Dor users. This working is responsible for the current cycles.
“Dor”, as covered in previous posts, can be translated as “great color/current” and refers to a specific kind of magic indigenous to the Areta Dora. “Theig” is a title for a hereditary leader, analagous to “King” or “Queen” in that there is no higher rank above it, and in that a theig's power over their lands and people is absolute. However, it is closer to “Lord”, “Lady”, or perhaps “Governor”, in terms of the usual scale of the lands they control, and in terms of how many theiga of equal rank operate within the same political system. A Dortheig, therefore, is someone who commands or rules over Dor; it is also an actual inherited title, with each island having its own Dortheig lineage. In between cycles, members of this lineage rule as ordinary theiga, unless deposed and replaced. Such usurpations rarely last long, but are common. When a cycle begins, any very young heirs of the current theiga are usually tested first, then other newborn relatives. This is done by a secret method known only to a few within the Dortheig lineages, which somehow involves the wellspring. Dortheiga always have Dor the same color as their island's wellspring (usually dark and richly saturated), so it's possible that the method involves color matching, but the ability to manipulate Dor doesn't normally become apparent until late in toddlerhood at the very earliest and the technique is supposedly accurate with newborns. Once identified, the new Dortheig is heavily protected and often placed in a secret location, where they are prepared throughout their entire childhood and adolescence for the eventual conflict.
“Nanumi” means “guardian” and is specifically associated with adoptive parents or found family in a situation where one's blood relations are deemed unworthy of familial respect or privilege. The Nanumia chose this name to emphasize that their dispute with the Dortheiga was about the ability to rule justly and compassionately, not whether Dortheiga were of sufficiently noble blood or had an adequate mastery of the Dor. (This argument was probably about equal parts good faith and cynical political maneuvering among early members of the Nanumi faction.) Prior to the conflict, “Nanumi” was not a title, and at the beginning of the conflict it was a term for anyone in the rebel faction. Now it applies specifically to the two self-spring Dor users of each island who are “destined” to lead this faction in each cycle. Nanumia always have Dor far on the ends of their color's spectrum. For instance, on the green island, one Nanumi would have extremely yellow-green Dor and one would have extremely blue-green Dor. At the beginning of a cycle, Nanumi supporters seek out very young Dor users whose colors are at the far end of the spectrum. Supporters then secretly move these children to islands of a non-adjacent color, where they will be completely unable to draw Dor of their own color unless they are self-springs (and therefore Nanumia), to test them. The Nanumia are then raised by members of the Nanumi faction and kept hidden from Dortheiga and their supporters until old enough to take charge.