what I always wondered shouldn't there be a sundered ascian part on each world like with our character as well? If Igeyorhm we killed in Azys Lla was from the Source she should have been rejoined 7 times. Apparently Ardbert and co killed all Ascians of the First. that would still leave 5 pieces of Igeyorhm around (maybe 4, depends how the 13th acts in this case).
Or do all pieces get erased when the Source piece is gone?

Also is Hydaelyn also sundered or is she present on all worlds?