Like Thunder

"This book begins with Dikâeogu Obidimkpa slowly losing his mind. Yes, that boy who can bring rain just by thinking about it is having some issues. Years ago, Dikâeogu went on an epic journey to save Earth with the shadow speaker girl, Ejii Ubaid, who became his best friend. When it was all over, they went their separate ways, but now he's learned their quest never really ended at all. So Dikâeogu, more powerful than ever, reunites with Ejii. He records this story as an audiofile, hoping it will help him keep his sanity or at least give him something to leave behind. Smart kid, but it won't work--or will it?"--

Nnedi Okorafor