Dark Chains: First Link by I. T. Lucas

She knew him as Yaaf, the scrawny boy with long legs and an infectious smile who was her best friend. Six years later, he’s back, and the boy has grown into a handsome man. Powerful. Disturbingly different. Is her friend still somewhere in there? Or has the brutal training camp beaten all kindness and humanity out of him?

Meanwhile, across the globe, Annani is at her wits’s end. The mission to retrieve the five chests containing Khiann and his companions is facing setbacks and complications, and she wonders whether the Fates are testing her resolve to move mountains to save her beloved, or whether there is another reason for the delays piling up.