Umbu Walu Mandoku appears in some recorded East Sumbanese origin genealogies as a founding ancestor paired with Umbu Walu Sasar, the two dividing and settling the island after the ancestral landfall. Sources differ on whether the founders are best remembered as a pair of brothers or as a single apical figure, and the name is transmitted with orthographic variation across the domains; the pairing is a recurrent but not universal feature of the oral tradition. Like other apical ancestors he is venerated as a marapu through clan genealogy and megalithic tombs rather than through an elaborate personal myth.