Bundy had the ability to come across as completely normal, was somebody people *****, seemed to be a kind and thoughtful and empathetic person. He had all kinds of psychological tests in prison and they found nothing frankly pathological although they did come up with some interesting characteristics we can discuss. Anyway he's something of a puzzle. Girls of the age he murdered would fall in love with him and want to be in the front row at his trials. Weird.
Keep in mind that at the time Bundy was being diagnosed, psychological understanding of serial killers wasn't as well established. There is still debate on the exact pathology, but you can read more about that here:
Ted Bundy - Wikipedia
As for the dogs' reaction, if it isn't a demon then I think you need some explanation. Their reactions were not normal reactions to strangers. What do YOU think they might have sensed?
Animals have far more acute senses than we do. Dogs especially have an extremely acute sense of smell. My suspicion is there was something about Bundy's odor that would invoke a negative reaction from a dog.
Note this come sometimes be completely innocuous. I had a friend that had a dog that often barked at me and not other people. And the reason was very simple: I had a cat and the dog had a strong dislike for cats. So the dog likely smelled residual cat odor on me and reacted accordingly.