Played by Carla Boudreau and Mel Harris, Oma Desala ("Mother Nature") is an ascended being who goes against the ways of the Ancients. It is unclear if she is an Ancient herself, as the Ancients Orlin and Merlin give different accounts of knowing Oma but it is likely as Merlin has a knowledge of her actions and he's over ten thousand years old. Although Oma once made the great mistake of helping the fallen System Lord Anubis ascend and is now banished by the Ancients, Oma is still convinced of her responsibility to guide those beneath to the "Great Path" of enlightenment, even if this interferes in the lower planes of existence. She and her followers walk a fine line between going against the wishes of the other Ancients and maintaining their rules enough to not bring down their wrath. Oma therefore only guides individuals to the path, leaving the final decision to whether to travel the Great Path to them.
SG-1 first encounter Oma Desala in a Buddhist-style temple on the planet Kheb in their search for Shifu, the young son of Apophis and Sha're. When a group of Jaffa attacks the temple, Oma Desala protects SG-1 and the temple in her non-corporeal form. Daniel decides to leave Shifu in Oma's care, and she ages Shifu to a young boy within one year and teaches him to suppress his evil Goa'uld genetic memory. Shifu eventually ascends with her help. Over a year later, Oma helps Daniel Jackson to ascend after his fatal radiation poisoning at the end of season 5. At the end of season 6, Oma helps Skaara and the entire Abydonian population to ascend after Anubis's attack, but she prevents Daniel from using his ascended powers against Anubis.
As Daniel broke the ascendeds' rules, Oma is forced to de-ascend him and to take away his memories (his idea) and abandon him naked on a planet (her idea). However, it later appears that Oma did not completely strip away Jackson's memories, but did in fact bury them deep in his subconscious. Oma Desala appears one final time to Daniel almost two years later in "Reckoning". Oma brings Daniel, who was killed another time, to an intermediate level between ascension and mortal existence and again attempts to convince him to ascend. After Daniel ascends for the second time, however, Oma sacrifices herself to enter into an eternal battle with Anubis to prevent him from wreaking further havoc on the galaxy.
According to Merlin, Oma focuses on the individual when she helps them out and while she has the best of intentions, Merlin counters this by saying so did the Ori when they started out.
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