 Alternatively, if the player chooses to purify the colony themselves, she will end up infested while desperately researching a cure, forcing Raynor to kill her.Arcturus Mengsk was the emperor of the Terran Dominion, which presided over the majority of the Terrans in the Koprulu Sector.The main antagonist of the series, he is voiced by James Harper and is the primary subject of the novel "I, Mengsk".