Mark Robson 
Dragon Orb: Shadow [EPUB ebook] 

Dragon”s in Areth each have a single predestined rider and a single life mission, given to them by the Oracle. But this once all-powerful being is now fatally damaged and fading fast… Only the dragons and their riders can save it!
Pell and his night dragon Shadow must find the dark orb to help save the Oracle, leader of all dragonkind. But Segun, a power-hungry tyrant, stands in their way. Pell must use his flying skills, bravery and resourcefulness to the limit, as Segun is determined to get the orb – even if it means killing the opposition…