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The Betrayal on Korhal was a battle in which Sarah Kerrigan attacked her former allies, who had already proven their worth. The battle ended with a decisive zerg victory and both Terran Dominion, Khalai Refugees and Raynor's Raiders forces broken and shattered.
The UED's remaining stronghold in the Sector was Char after the loss of Korhal. Kerrigan no longer needed her allies, and moved to cripple the Dominion and Praetor Fenix's protoss contingent before leaving the planet. She accepted Samir Duran's advice to attack immediately while the terrans and protoss were still resting from the last battle; resistance would be minimal for a few minutes while the enemy rallied.
The intervention of General Edmund Duke aboard Norad III was unable to salvage the Dominion's position. Duke died with his battlecruiser, fulfilling Kerrigan's prior wish to have him killed. Mengsk was outraged by how the Dominion had been used to cripple the UED and ensure Kerrigan's control over the Swarm. As revenge, Kerrigan left Mengsk alive to nurse the crippled Dominion; living to see her rise to power would be a reminder of his part in turning her into the Queen of Blades.
Fenix also died fighting, belatedly realizing his doubts about Kerrigan's trustworthiness had been true. Kerrigan noted the protoss' own "headstrong and predictable" nature had made them perfect tools. Furthermore, this had made the protoss their own worse enemy, ironically echoing Tassadar's lesson to her during the Great War. Fenix's death roused Raynor to anger. The rebel vowed to kill Kerrigan in the future to avenge those who had died during her ruthless pursuit of power.