Well, Neegan's back story is quite dark. He came from a world that had fallen apart. He built up his power base gradually. His actions were often brutal as he aimed to keep his group in control. He believed in his own way of survival which involved subjugating others. His past might have been filled with hardships that led him to become this tyrannical leader. For example, he might have seen too much chaos and decided that the only way to survive was to be the one in charge, and that's how he formed the Saviors and started ruling over other communities with an iron fist.
Well, Neegan's demise in the comics comes after a series of intense battles and plot twists. It's not a straightforward death but rather a result of multiple factors and interactions with various characters in the story.
Neegan meets his end in a rather dramatic and unexpected way in the comic books. It involves a series of events and confrontations that lead to his ultimate demise.