Divine twin

The Divine twins are a mytheme of Proto-Indo-European mythology. Examples include the:

The Yoruba orishas Ibeji are a similar example outside the Indo-European realm.

O'Brien (1982) reconstructs a horse goddess with twin offspring, pointing to Gaulish Epona, Irish Macha (the twins reflected in Macha's pair, Liath Macha and Dub Sainglend), Welsh Rhiannon, and Eddaic Freyja in the tale of the construction of the walls of Asgard, seeing a vestige of the birth of hippomorphic twins in Loki in the form of a mare (in place of Freyja) giving birth to eight-legged Sleipnir. The myths surrounding Hengest and Horsa could come from a common source, since they were descendants of Woden and Hengest's name meant "stallion" (in German: Hengst) Shapiro (1982) points to Slavic Volos and Veles, and collects the following comparative properties:

One recurring element in the divine twin theme is that, while identical, one is divine and the other is human. This points to other characters which partially reflect the mytheme, such as:

...
Wikipedia