Due to the similarity of "Aona" and "AonDor", it seems likely that Devotion is related to AonDor and Elantris.
The Aons at the heart of the Seons are Splinters of Devotion.
The Splintered remains Devotion and Dominion make up the Dor together. Dominion is why nationality and the land is a focus for many forms of accessing the Dor, but it is unclear how Devotion affected it. One way is that Elantrians must be devoted to something to be taken by the Shaod, but this does not explain Forgers, ChayShan practitioners, and Dakhor monks.
The only known mention of Aona is in The Letter. Before the events of Elantris, Aona was killed by Odium, and Devotion was Splintered.