From Halopedia, the Halo wiki
Scion is a Sangheili noble title, typically held by Sangheili females. The title is applied upon the death of a keep's given kaidon. While female Sangheili, by tradition, may be mistress of their keep and ruler of their kaidon husbands, they may never become owner and heir to their father's lands and posessions. If the Scion is the only remaining living member of the house, lesser kaidons will vie for the Scion's inheritance by attempting to secure their marriage for themselves or their sons. The Scion is able to refuse such offers, with many Scions in Sangheili history being notable for having done so for years or decades. Some such as the Gray Maiden of Konar lived their entire lives in perpetual siege, fortified in their keeps and aided by loyal vassals and the foolishness of rival kaidons who wasted decades fighting among themselves. Scions, due to being female Sangheili, were typically not able to request the right of release, though Scion Tul 'Juran was succesfully able to do so following the Attack on Rahnelo. In the years since, the Scions have become more valued and respected as Thel 'Vadam's influence has grown.
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