when Gorosei asked Imu to tell them what is the light that should be erased from history? her answer was probably Lulusia kingdom, we have misleaded because she was holding Vivi's picture, & that makes sense, because the Gorosei in this chapter said that it was Sabo's bad luck that he was in Lulusia, which means that the erasing of Lulusia was already decided even if Sabo wasn't there, that also means that the Gorosei takes Imu's order & then they use Uranus to do her order, it means that the Gorosei are ones who control Uranus.
we also know now what they by erasing a country from history, they simply use the ancient weapon Uranus to erase that country, that's how the Great kingdom was destroyed, it also appears that Uranus is the strongest ancient weapon if that weapon was really Uranus