If you do the 5th role quest you learn that the Ascians purposely forced the First to be flooded with light and then were going to use this to undo or nullify the flood of darkness on the 13th enough for it to be rejoined. So, it is possible in theory for the 13th flood to be reversed. Now this would save the aether but not make it hospital by any means. The 13th has been a dark void for at least 10,500 years. All beings on the 13th have likely been voidsent for that long or are born from existing voidsent. There's likely no bastion of civilization left.