I never knew about him until playing the SE. I love the way this game throws out little surprises after five years. I found a trail of blood leading up into the mountains south east of Riften and it lead me to a troll eating a dead body with a strong box nearby. Nothing special but cool just the same. Anyway, I found the dragon in Blackreach by shouting at the 'sun' and I was surprised that there wasn't more to him. I figured he would have some cool Easter Eggy type thing about him but he isn't even a very difficult dragon. Is there any mention of him in a book or something? Anyway, kind of a letdown I guess.