There are fanfictions where Daryl and Glenn form a pact to protect a particular group of survivors. In these stories, they often use their unique skills - Daryl's tracking and survival skills and Glenn's knowledge of the area - to keep everyone safe. This creates a lot of interesting interactions between them as they work towards a common goal.
They add new dimensions to the characters. Fanfiction allows writers to explore aspects of Daryl and Glenn that might not have been fully developed in the show. It gives fans a chance to see different sides of their relationship, like a closer friendship or even a brotherly bond.
Glenn does die in the comic. It was a tragic and impactful moment that changed the course of the story. The circumstances of his death were intense and left a lasting impression on readers.