Some common themes in fanfic about their love include the idea of family. Even if it's not a traditional family relationship, it has elements of family - like love. Another theme is the power of connection. Their bond is so strong that it can overcome many obstacles. Also, the theme of hope. Their love can represent hope in a world that seems so bleak. Fanfic writers like to delve into these themes and show how Ellie and Joel's love can be a source of strength and inspiration.
One common theme is protection. Joel is often portrayed as protecting Ellie from all kinds of threats in the post - apocalyptic world. Another theme is growth. Ellie grows up with Joel's influence, and their love is shown as a factor in her development. And of course, loyalty. They are loyal to each other no matter what difficulties they face.