Kilysa is a broodmother and leader of the Kilysa Brood.
When Kilysa asked to rejoin the Swarm, Sarah Kerrigan ordered her to destroy Mistaff IV to gain a place in the Swarm.
She assisted Abathur in collecting the essence of old lurkers on Cavir.
Her brood also attacked Cruxas III.
Kilysa collected two-way communicators that Emperor Arcturus Mengsk left for Kerrigan on Char.
During the invasion of Korhal, Kilysa had her leviathans form a blockade and hold off Terran Dominion fleets coming into the Korhal system.
Kilysa played a role in Heart of the Swarm's cut Destruction of Worlds mechanic. The player could send her to destroy Haven, Bountiful, or Bhekar Ro. Her name was initially spelled "Ki'lysa."