On Aiur, the protoss Conclave had lost contact with Tassadar’s expedition force. They swiftly promoted the young templar Artanis to Executor in Tassadar’s place. Artanis and his allies (including Praetor Fenix, a life-long warrior) fought to drive the zerg back, but they were sorely challenged.
Tassadar managed to contact Aiur from his position on Char, and share vital information: if a cerebrate were killed, a large number of zerg would become disorganized and fractious. Aiur’s defenders attempted to slay an invading cerebrate, but failed, and the Conclave branded Tassadar a heretic when they learned that he had allied with Dark Templar on Char. Fenix and Artanis fought pitched battles at provinces throughout Aiur, but the protoss gained no ground, and Fenix was slain while attempting to repel zerg invaders at Antioch.
Protoss joined Tassadar on Char, but rather than inviting his forces to rejoin the war effort, they stripped the Executor of his rank and arrested him. Though commanded to return to Aiur for trial, Tassadar shared an observation with his fellow protoss: the void energies of the Dark Templar could permanently kill cerebrates. He convinced Artanis to rescue Zeratul, who had been penned in by Dominion forces on Char, and join forces with the Dark Templar so that they could strike at Aiur’s cerebrates together. Artanis led his Khalai protoss and Zeratul’s forces to Aiur, but the presence of the hated Dark Templar on the protoss homeworld led to riots and civil war.
Horrified, Tassadar sought to overthrow the Conclave for the sake of the battle against the zerg, but ultimately surrendered himself to their judgment rather than promote further bloodshed among his people. Though Tassadar was jailed, Jim Raynor and Fenix (who had been reconstituted in the shell of a war machine called a dragoon) sprung him, and Tassadar assaulted the Overmind. Drawing on Zeratul’s teachings, Tassadar channeled both Void energy and the Khala of the Aiur protoss into a suicide strike on the Overmind with his flagship, destroying it at the cost of his own life.
