Mashu notes that Taira-no-Kagekiyo is a figure of the end days of the Heian Era — a warrior of the Kanmu Heishi (桓武平氏, "the Heike of Kanmu").
He was a figure that sought vengeance against the Genji, who had by annihilating the Heike established a Shogunate. His objective in particular was the assassination of Minamoto-no-Yoritomo.
Numerous legends have circulated about this figure, but most striking amongst them was the legend of his immortality.
Mashu isn't certain as to the thaumaturgical implementation of the phenomenon, but it was said that Kagekiyo would revive even after being beheaded.
Medb asks why it would be that such a figure would come to inhabit a Saint Graph belonging to Ushiwakamaru.
Medb: "Could it be that two distinct Heroic Spirits coexist as of that Saint Graph?"
Hougen observes that Kagekiyo and Yoshitsune are both borne of numerous legends; that, further, despite being of the Taira and the Genji respectively, they're in some regards kind of similar.
If there can be said to exist a difference between them, it would be that Kagekiyo is a legend not derived of historical record, but a legendary existence come to instantiation of a heroic tale.
An existence absent of form as of historical record — not particular bizarre in capacity of a Heroic Spirit; but to Hougen's senses, even setting aside that Kagekiyo is absent of historical grounding, she's absent of an actual form.
Rather than a Heroic Spirit, says Hougen, perhaps she's something more approximate to a grudge spirit.
