Tale of Otharios - The Knight of Tranquility

The Knight of Tranquility is my first in a series of short stories entailing the lives of individuals from a fantasy land. Each tale is intended to be a piece in a literary mosaic requiring knowledge of multiple stories in order to see a full picture. This first installment in the Otharios collection follows a low born boy named Duke who becomes a first rate knight and battles malicious magic users known as Hexiles. Can you figure out the TRUE ENDING from the clues I've provided?