Sarah Kerrigan is the primary hero unit of the StarCraft II: Heart of the Swarm campaign. She initially appears very human, and is armed with a rifle. After the first three missions of the campaign are completed, she leaves her rifle after a while and resorts to shooting psionic shockwaves from her hands. In Heart of the Swarm, the campaign operates similarly to an RPG. Kerrigan focuses on increasing her personal power through mutations while the zerg protect her.