[Source] The Dagger of Mortis, simply referred to as the Mortis Dagger, was a mystical weapon that resided on the Altar of the Wild Space world of Mortis. The weapon was kept hidden on the realm of Mortis by the Father, who kept it as a means that could control his children, the Daughter and the Son. The weapon was capable of controlling the sibling pair of powerful Force wielders, and it was also capable of killing them, if necessary. When used on the Father, however, his death at the hands of the dagger would rob his children of their immortality.