The Battlemage (Summoner Trilogy Series #3) by Taran Matharu

The epic conclusion to Taran Matharu's New York Times bestselling epic fantasy Summoner Trilogy, The Battlemage is an action-packed adventure of a young man gifted-or cursed-with an extraordinary and terrifying power… Fletcher and his classmates from Vocans Academy-including the elf Sylva and the dwarf Othello-travel through the ether, where they must pursue a mortally dangerous quest to rebuild their world and broker peace. As he leads a small army of soldiers, Fletcher will face his biggest challenge yet: his nemesis, the albino orc, Khan, who seeks to destroy everything Fletcher loves.