The Rod of Seasons, a Force artifact, had the ability to exert influence over individuals belonging to the Nameless species. While the staff alone could draw a Nameless to it and provide a certain level of command, complete domination over these beings required the combination of the Rod of Seasons with the Rod of Daybreak, resulting in the creation of the Rod of Power.
As one component of a trio of control devices, this particular rod was at one time held by the Hynestian royal family. It was later taken by members of the Path of the Open Hand, a cult that advocated for the Force's liberation from Force-users like the Jedi.
Zallah Macri and Kevmo Zink, two Jedi, journeyed to Dalna, the location of the Path's headquarters, with the objective of retrieving the artifact. However, they met their end at the hands of a Nameless creature known as the Leveler. Subsequently, Yana Ro, a member of the Path, discovered the rod's ability to attract the Leveler. Following the events of the Night of Sorrow, Marda Ro managed to escape, taking the Rod of Seasons with her.
Roughly one and a half centuries later, Marchion Ro, the Eye of the Nihil, possessed the rod. Driven by a desire for vengeance against the Jedi, he sought out another one of the rods and the Leveler as integral parts of his elaborate scheme. Ultimately, he succeeded in reforging the Rod of Power.