I think that N'zoth is not the corruptor of Northern Kalimdor and the Barrens, I believe it's a separate Old God.
I'll copy from my other thrread:
---------------------------------------- My speculation
Last one, is the old god in the
Barrow Deeps. Proof:
-
Faceless ones and tentacles in Stonetalon Peak,
quest conversation (click links for proof, thanks to Darkside for pictures)
Speculation
- I think the God is behind the corruption of the Barrow Deeps we got to visit in Warcraft III. There were crazy mutated monsters, Furbolgs going mad, and druids stuck in their bear forms, unable to get out and attacking even their long time friend and mentor Malfurion. Why would that be? I don't think only time could make the Druids go mad and think they're bears I suppose we have seen that concept somewhere already, no? Vordrassil. World trees seem like a good medium of corruption for the Gods for some reason. Well, if the Old God got rid of the Druids, Hyjal's defense would be much weaker and the Night Elves would lose their immortality (which they did in the end anyway, but the Gods want to eliminate life from Azeroth)
- The same fate probably met Teldrassil - just like with Vordrassil, it's roots fell to the corruption of the God, and the creatures and Furbolgs in the treetop got corrupted.
- Bloodstone ore is also found in Stonetalon mountains. WoWwiki:
And there's also Soggoth in Darkshore and many Twilight Camps in Darkshore and Hyjal.