Board Thread:General Discussion/@comment-3471274-20130606153913/@comment-74.82.17.87-20180829143718

Vultheryol and the dwemer probably had some sort of friendship. Vulthuryol might not have wanted to fight so he asked the dwemer to allow him to stay in blackreach and in return he would protect it if any other race decided to attack it. when the dragon born summons him he is probably afraid for his life as he probably knows what dragonborns are capable of.