As Ted Peters once pointed out, in the English language, it's curious that the word evil is "live" spelled backwards. And indeed, evil always destroys. Life is diminished if not wiped out where the demons rule. The death of the pigs reflects that. What's more, in the Ancient Near East, the sea represented one of the forces of chaos that people feared. So it's a double-whammy: first there is death but second there is death by drowning in the sea, thus piling up and compounding the sense of chaos and evil in this story.

But …