Unfortunatly I cant say I know anything about Eberron or any of that lot. I seem to be rather ignorant to many thing discussed frequently here, quite annoying realy.
But...an NPC I quite like is my silver dragon. Heres how its gone in my campain...The players are heading down a mountain side road when they see a elven maiden surrounded by a band of orcs. like heroes do they rush over to help, and dispatch the bandits. They dont know that being a young silver dragon, the 'damsel in distress' didnt need any help, but she lets them do their thing regardless. After the fight she plays along and thanks the 'grand heroes', she remains in her disguise (as silver dragons love to do) and tells them shes trying to find a large city, which she has trouble nameing, which surprises the players after figureing out that she speaks of Arvenhold (the big shiny capital city in my game world) and surely everyone around should know of it (its her first time far from her little cave and starting hoard given by her unknown parents, also her first real encounter with people other than orcish tribals here). She offers to pay them as guides, they agree but are surprised by the amount she offers as payment (unsure of its value amoung others yet), and how much gold and plat shes carrieing (nearly a whole pack full). They guide her along, endureing an endless barrage of strange questions from their naive employer, all of a sudden they are horified as a bulette bursts from the ground below her and sends her flying. To their amazement she gets up reletively unharmed, looks undecided for a moment, and then asks for a weapon. battle...blah...blah...etc. Eventuly they get to the city, she hangs around them for a while, being intimidated by the strangeness of the city. etc, etc.
Thats roughly as far as they are with this side of the campain, they havent found/figured out her indentity yet. Its quite cool haveing them not know who she is the whole time. So far my players have settled on the idea that she must be high level or something, but dont understand why she seems to know so little.This NPC could work nicely enough in almost any campain, I think. You can choose any name, city name (use your own local big city), time they meet, etc. This could even be done realy early in the campain, even at first level (just remove or swap that bulette of course). It would be cool for the players to have known her for ages and then finaly the shock of her turning into a dragon some time. In my campain my idea is that when they find out she'll be a useful ally, and play a part in a fight against a other larger dragon.
Hmm...I didn't mean to write that much. oh well.
So there you go, thats my NPC for you, use if you like. Hope this is useful.