The spheres had the ability to merge with the conscious personality of certain humanoid species, enabling the personalities of the most prominent members of the original power struggle to emerge and infect anyone who came in contact with them. Eventually this would cause the "hosts" to re-enact the disastrous events that destroyed the Saltah'na.
In 2369, the Klingon starship IKS Toh'Kaht traveled to the Gamma Quadrant and encountered the spheres and fell under their influence, which it then transferred to Deep Space 9 shortly before the ship's destruction. The crew of that station began to re-enact the Saltah'na struggle all over again. Fortunately, Odo was unaffected as he was not a humanoid being, and he managed to trick the influenced Julian Bashir into undoing the influence of the spheres by emitting an ionic interference signal using the program known as Odo One.
Benjamin Sisko, whose personality was supplanted by the deposed ruler of the Saltah'na, constructed a clock of unknown design while under the control of the spheres. Even after the spheres' influence wore off, Sisko kept the clock and displayed it in his office. (DS9: "Dramatis Personae")