the dominant religion in ashey's town holds the idea that god is reborn as a person every generation, and they proclaim a particular persons godhood and venerate them throughout their lifetime until they die and then a new god is proclaimed. there are of course MANY branches, so throughout the world there are many different people worshipped as gods. in some places this difference in belief is treated with tolerance, but in large portions of the world its illegal to practice other religions than the dominant one. in many countries gods are the head political rulers, with mages serving as lower ranking political rulers within the country.
ashey's town is in one of those countries, and the majority of townspeople are members of a small persecuted apocalyptic sect that believed the world was going to end with the death of the country's (ex) current ruling god.
(side tangent: this death sends the country into a weak period as they have no head ruler and must wait for their new god to reach adulthood. the god of a more powerful neighboring kingdom has strategically chosen this time to start trying to take over and enforce their godhood.)
on the night of their god's death, shourn as the ruling mage was leading a ritual for this expected end of the world. ashey, questioning if it was even going to happen, wandered off to the nearby flower field to be alone and chew her drug of choice. a star, though a bit different from our own stars, soared through the universe and reached the planet's atmosphere, crystallized, and collided into ashey, miraculously leaving her mostly unharmed but lodging in her chest. she was already high and this left her disoriented; regha, who had been looking for her, found her still lying where she was.
i'm fuzzy on the details from there but now ashey is not only a mage but most of the town thinks their god chose her to be their savior and that the apocalypse was cancelled or just delayed. shourn, who has a complex about being raised to feel special for their magic, is not taking this well. neither is ashey.
(another side tangent: ashey's name is very popular and translates to both "star" and "sanctuary", stemming from the belief that stars are the sanctuaries of god's past lives. those past incarnations are still venerated to varying degrees, and have specific stars associated with them.)
there is much more i could say but i'm incredibly stoned and i struggled to write this. bye