"Sarah Louise Kerrigan, the self-styled Queen of Blades, is a major character and the predominant antagonist in Blizzard Entertainment's StarCraft series.
Kerrigan originally appears in StarCraft as a twenty-six year old female Terran psychic, trained as an expert espionage agent and assassin both physically and mentally. Initially the second-in-command of the Sons of Korhal, a revolutionary movement headed by Arcturus Mengsk against an oppressive Confederacy of Man, she is captured by the insectoid Zerg and infested, turning her into a human/Zerg hybrid completely under the control of the Zerg hive mind. She becomes one of their most powerful agents, but eventually usurps the Overmind control of the Zerg to seek dominance over the galaxy"
Source: Wikipedia, "Sarah_Kerrigan", available under the CC-BY-SA License.