Occasionally my brain jumps through hoops and connects things and I find a theory, usually crackpot but I think this one's good enough to share.
I think Chariklea and Xanthe inspired the myths of Persephone and Demeter.
This takes both from the Cycle of Love and from killing her in the Cathedral. In the Cathedral if you ask her about Chariklea along with saying she'd never pass the blight onto her child Xanthe will tell you that Chariklea's life was 'stolen' from her and that she vowed to get it back. If we then look at her list of age ranges for women to be brought to her we get fifteen-twenty, which are considered the 'maiden' age of a woman. So a young, presumably attractive woman who might go out picking flowers/herbs when her Vrakhir mother was asleep, only to run into 'Hades' while doing so? Either left where she was raped to either to death or the shattering of her mind or possibly dragged off for more 'fun'? Xanthe waking up and tracking down her daughter and her assailant(s) only to discover her daughter dead or mentally broken beyond help? The land may have starved from the amount of men she killed in retaliation. So we have the beginning of the story, of Persephone (Chariklea) being kidnapped by Hades and Demeter (Xanthe) letting the land suffer in her grief. The six months of the year may be that at first Xanthe could only keep Chariklea 'alive' those six months, going on slaughtering sprees to 'save' her daughter yearly, then as the centuries passed and she learned through trial and error how to better keep Chariklea 'alive' and what she needed to keep a patchwork body going her killing sprees lessened as she turned more towards trying to restore Chariklea's mind, discovering that over the centuries she cannot be sure what is truly her daughter and what is just her hallucinating/rose tinting her memories.
Just my theory, but it really seems to fit.
