Onashia
オナシア
Onashia is the High Priestess of the Tempus Spatium, and presides over the gender selection ceremony at the Spring. Daikuurikans are born female, and choose a sex at age 17; in Simulacrum, this is done by going to the Spring at the temple of Tempus Spatium. As head of Simulacrum’s High Council, she serves as head of state.
it is hinted that Onashia is actually Dominura.In Dominura’s last scene, while she walks, we can see sparkly gold flakes in the ground, like the ones that Onashia shows Yun. When Onashia dissappears, Yun calls out Dominura’s name as she peers into the Spring.