Complex sentence: The "Gradiva, The woman who walks," has become a modern 20th century mythological figure, from the novella Gradiva by the German writer Wilhelm Jensen, as she has sprung out of the imagination of a fictional character she may be considered unreal twice over.
Split into simpler sentences: The "Gradiva, The woman who walks," has become a modern 20th century mythological figure. As she has sprung out of the imagination of a fictional character she may be considered unreal twice over.