While Tia worked on a fix to the truth serum, which was required to extract the information Erich needed from the Sages, he took as a prisoner. Erich himself had begun to set his eyes on another target. He honestly did not know if the Sages were hiding in one centralized area for the most part, or if they had been scattered across the galaxy.
But from the sounds of it, the bulk of their order was hiding somewhere remote. After all, every sage he had come across thus far had told him that only a Greater Sage First Class would know of their whereabouts. Because of this, Erich felt that he needed to have an army of his own, if he were to storm the world and eliminate the so-called prophets of fate.