Primordus
We know where Primordus is, he’s in the depths of Tyria, which is why Asura and Skritt live above ground, and why the dredge are also moving upwards. Sure, he is known to be able to create minions out of fire and stone, but not limitlessly, as otherwise we’d be up to our shoulders flooded with destroyers. Zhaitan needs to feed on magic (which he does by devouring magical artifacts through a special minion), I’d guess Primordus needs to feed on magic as well to power it’s minions. And the more powerful the minion, the more it probably needs magic to keep up.
It’s very likely that the source or sources of magic that Primordus is consuming comes mainly from Asuran technology developed before they moved out of the depths, just like Zhaitan’s primary source of magic to consume came from Orr where the human gods resided. The Ring of Fire would make sense for a dragon as well because of the ruins of the Mursaat fortress located there, which is sure to be full of magical items.
Actually if you think about it, the Dragons have all been very decidedly near Magically saturated areas. Primordus being the exception that we don’t know precisely where he is, but the fact that there was a magically saturated nation (Asura) living underground makes for a prime feeding ground for him. As does the Ring of Fire if Anet ever deign to let us return there.
The other Dragons seem equally concentrated on these types of areas, with maybe Bubbles being the biggest ‘well we dunno’ due to the whole ‘could be anywhere in the freakin’ unending ocean’. Kralky went to the Desert which was not only a home for the Forgotten, but also a home for humans from Elona seeking assension but also the place of Augury Rock and the Tomb of Primeval Kings, two very magically linked area’s in the game.
The Jungle Dragon has been hinted at being in the Maguma Wastes, the former home of the Druids, who’s even empty husk like bodies are said to contain magical power. I also doubt we’ve seen the last of these once human creatures so it’ll be interesting to see how the story goes for that end of the boat.
I won’t repeat Zhaitan since I think Narcemus covered that one more than adequately. It’s fairly obvious why he was pretty happy to just chill out on that peninsula.
Finally there’s also Jormag. Though there are no direct magical fonts of power that he seems to be aiming for directly that we know of (if I remember he descended from further north than even the GW1 map depicted). He has however made significant attacks against both the Kodan and their Sanctuaries which are not exactly lacking in magical artifacts. I think the biggest anomaly with Jormag is that the Eye of the North, though abandoned, is remarkably not under seige by Jormag which I think suggests either it has lost its magical nature or that it’s magic is derived by something that we don’t quite fully understand yet.
Primordus can make minions out of lava and stone, but it’s a slow process – slower than making minions out of living beings at least.
Yes, he could make another Great Destroyer – there’s a book in Divinity’s Reach that says dwarven legends mention an army of Great Destroyers, in fact. But the same can be said for all dragon champions – any Elder Dragon can make hundreds of dragon champions. I mean, watch the sky during the Arah story dungeon when you get to the dragon champions. Though you only face 3, there’s at least a dozen in the background – if not far far more, and then there’s all those over the skies of the Orr zones, Blightghast that attacked Claw Island, and the dozens of Tequatls.
Take note that Tequatl, Shatterer, and Claw of Jormag aren’t a single dragon that re-appears, the lore is that each event is its own dragon.
The Ring of Fire would make sense for a dragon as well because of the ruins of the Mursaat fortress located there, which is sure to be full of magical items.
Don’t forget the bloodstone or the Door of Komalie.
Someone tell the Pact to get their arses to the Ring of Fire pronto. It’s an Elder Dragon buffet right now.
Stop treating GW2 as a single story. Each Season and expansion should be their own story.
And we know that Zhaitan had at least some interests there because it’s mentioned many places that his navy ran a blockade from Orr to the Ring of Fire islands. I would very much expect them to bring back magical artifacts while there. I think the only reason that he didn’t go there to get at the bloodstone or the portal to the mists is because he already had so much as it was.