This is more worldbuilding than plot creation but we don't have a world building forum and it will impact on plot. I am having one of those cleaning and meditating on story times and came up with a thought - not sure it makes sense yet so bear with me. The number of sets of twins in my books has always concerned me a bit its a bit cliche for fantasy (I have around four sets - one created themselves arrived that way, one were necessary for paternity reasons, the other two for description reasons (reduced the amount of description for different races). I just put it down to me growing up with them (twins run in my family and in a primary/elementary school class of nineteen we had four sets). Anyway the main theme of my stories is balancing a universe that is a living organism. Each of my twins are descended from the Abbot or the King. They are usually the heirs. Would it be weird to have the reason being they are needed for balance? Also in the case of one set they were actually born eight hundred years apart but still have the connection ? This happened when the set of twins supposed to take the place of the King and Abbot messed up and couldn't.