I think a lot of the details on pelinal are just metaphors or over exaggerations. Bethesda did a great job of leaving holes and broken pieces to the story, making it really feel like we're deciphering old texts and trying to figure out what all of it really means. Records indicate that he lacks a heart, which commonly means he doesn't have compassion or mercy which would make sense. He later makes friends with the bull and it really humanizes him to me. My theory is that he has Extremely close ties to Akatosh and Shor, maybe even being controlled by them. Being controlled by two opposing Gods seems like it would have catastrophic effects on a persons mental stability but that could also explain his immense power.