Code Geass did start as a manga. However, its anime version became even more widely known and beloved. The manga provided the foundation for the rich story and characters that were further developed in the anime.
Code Geass started as an anime. The manga was based on the anime's success and came after to expand the story for fans. Some elements might differ between the two, but the anime was the original form.
In Code Geass fanfic, Nunnally is often a complex character. She is usually depicted as a symbol of innocence and hope. Writers might explore her relationship with Lelouch in different ways. For example, some fanfics might focus on how she would react if she knew all of Lelouch's secrets and plans. Her blindness also adds an interesting layer to her character, as it can be used to show her inner strength and vulnerability simultaneously.
Sure does. The manga version of Code Geass expands on the story and characters from the original anime. It offers additional details and perspectives that fans enjoy.