u/Dismal-Silver8925

I need some help. My mother cannot remember what the book was called that she read in her teens during the 1980s. All she can remember is that there is a male character named "Bren" who rides a dragon-like creature. The world of the series is full of floating islands and she believes the word "shattered" is in the title. Any help is appreciated, wanting to get a copy as a gift for her