Sorry to sneak the chapter on you Nothingsp... I just for some reason wanted to explore the science of the sun and this just came up... I do want to get back to the haunted library ;)
Regarding Anezza... An interesting idea, but it still feels a little too deux-ex machina to me. Anneza does have the capacity for this on her own I think, without a godly intervention. It will take time... and I would consider this just lashing out as impatience. She's still struggling with a female identity too and very limited wardrobe, plus... the idea of a lost girl ranting at the sun, was just such a thought provoking image to me.
Why not just have Mercury say a single sentence in her language? That will make her feel better and inspire her to keep at it.
Finally... I would not rush to fix Aneeza's language problem. It's so much a part of her story, that it can't be just waved away, and we would take away something special and unique in the universe too. I have always wondered where the language came from, and how it alters the very concepts she may have.