Board Thread:Skyrim/@comment-1157147-20130322022136/@comment-213.143.72.174-20130527115330

Vulthuryol is essentially an Easter egg, so to speak, as he can only be encountered if you just happened to use Unrelenting Force on the huge orb (which, let's admit it, not a lot of us would do if we hadn't read about it on the wiki). As any Easter egg in any game, its purpose is mainly to reward a player thinking out of the box with either tresure, or in this case, a semi-boss fight.

As for his integration lore-wise, the fact he crawls instead of flying as well as being in Blackreach to begin with provides evidence enough that Vulthuryol probably stayed underground and, as has been noted on the page, his identity or whereabouts were possibly never discovered by dragon hunters.

It does however beg the question whether or not Vulthuryol had been inhabiting Blackreach already when the Dwemer found it, or moved in after their demise. The latter seems improbable, as the timelines do not match exactly (unles the dragon evaded his enemies for several centuries until finally settling in Blackreach). However, were he present in the time the Dwemer walked the same cavern, you'd think there would be some mention of a dragon in their midst (at the very least how they managed to convince him not to eat them).

P.S: "wreck" -> "wrecked," but "wreak" -> "wrought"