The Lost Treaty by Hunter Solomon Regenold

Alex Vennenzula feels cowardly when his father, the king of Eckle, sends him to the small, strange town of Splitzerhein, because he has a strange feeling that his greatest enemy, Haletrone, will somehow rise from the dead.
Everything changes when Alex meets with a trio of royalty, who show Alex a forgotton treaty, a treaty that would unite the three kingdoms of Selecsalsair in the fight against the sons of Haletrone, who are trying to raise their father using a Life Bind.
Alex and his friends journey across Selecsalsair, through infested forests, over poisoned rivers, and between razor-sharp mountains. They must fight a myriad of grotesque, evil Ogres, battle in burning cities, and defend against gruesome sea monsters. Along the way, Alex learns of an undying, unconditional love, the loyalty of friendship, and the bitter-sweetness of looming sacrifice.