I know this old, but lets be honest, does it really matter which dragon is next or last? Here is why, given that we learned about the dragons sharing the powers of a downed elder dragon leads me to this idea... The elder dragons are just avatars of the TRUE source of all magic in the GW2 realm. That like Lazarus, what we are seeing are specialized fragments in order to spread the absorption of magic quicker and better (like the mouth of Zhaitan and Mordremoth). And maybe the ley line anomalies, bloodstone mad Mursaat, loose magic, and maybe even the Eternal Alchemy, are all tied to this TRUE source and because the various life forms of Tyria are leeches and parasites that is actually draining this TRUE source and so it does not get to weak or is killed, it has to survive by ridding itself the the leeches and parasites? That the elder dragons are actually antibodies that are curing and healing the TRUE source?