Theon Greyjoy has regained his honour this season first by stepping up to save his big sister Yara from the clutches of their duplicitous brother Euron and then by arriving at Winterfell to help defend against the White Walker threat. Wouldn't the perfect finale to his redemptive arc come in the form of slaying the Mad Queen? Reddit user SculleryWench doesn't think the idea is so farfetched citing several places in the books and the HBO series where Yara refers to Theon as "little brother," a direct tie to the prophecy and an element of foreshadowing to obvious to overlook.