Threnody

Okay, so things are still nebulous in my head but I think that Cusicesh the Protector has something to do with Urithiru. Urithiru is described as being riddled with pipes/tubes and carved pools where water would have been. Cusicesh is water-like and displays hundreds of different faces each morning when it arises from the Inland(?) Sea at Kasitor. Faces it would know from being surrounded by hundreds/thousands of people in a city. It is also named the Protector - Urithiru's protections are described as weakening in the crystal records. The Sibling is described as "they" by the Stormfather and there is the image of the blue pool and figure with arms outstretched. I think this is the Sibling, who is related to Stone, who works with Cusicesh (a blue water-like spren) at Urithiru. I suspect that the destruction of the city at the Shattered Plains may have damaged/weakened the Stone Sibling, hence it withdrawing and slumbering. Melishi (Stone Bondward) capturing BDO in the crystal may have been the final straw and the Stone Sibling went into slumber. I'm also intrigued at what is going on with Aimia. When did it get destroyed? We know "recently" and it still was intact when the crystal record at Urithiru was created. Could this have something to do with the slumbering Sibling?