Edit: Deep Sea Dragon isn't included since the players have never seen, nor fought the deep sea dragon nor its minions and we know nothing about it.
Weird and oddly specific question, but it's thought provoking and brings up good questions about yourself:
If all 10 million of Guild Wars were to get on simultaneously to fight all 5 Elder Dragons at once, and they were split up into groups of 2 million to fight each dragon and its minions, which do you feel like you'd specialize in?
Zaithan and the Risen?
Kralkatorrik and the Brranded?
Jormag and the Icebrood?
Primordius and the Destroyers?
Or Mordremoth and the Mordrem?
Which do you feel you'd be the best at fighting, the most knowledgeable about, and the most confident in fighting?
Ultimately: Which dragon would you fight?