During the early stages of the End War, Probius took part in the Reclamation of Aiur as part of an akhundelar under Kaldalis. During the initial landing, Probius was able to set down a warp beacon for a pylon while the conflict raged around him. Though the akhundelar suffered heavy casualties, Probius's pylon allowed reinforcements to be warped in at a key moment, allowing the Daelaam to establish to a beachhead on Aiur.
This article or section contains information derived from Co-op Missions, and should not be considered part of the official StarCraft storyline.
Probius appears in Co-op Missions as an easter egg when playing as Fenix. If the player has researched all six AI personalities at the purifier conclave and have them all out on the field at once, the next probe they warp in will become Probius. Probius has no unique benefits and will not transfer to another probe if he is destroyed. If Probius is destroyed he cannot be respawned, even by building more probes.
Probius' addition as a hero unit in Co-op Missions makes it the first hero unit worker in the series.
While bravery and curiosity are not regularly aspects programmed into protoss probes, Probius's personality is explained in Heroes of the Storm as having gained this divergent personality upon being warped to the Nexus.
While Probius is stated to be the probe in the Legacy of the Void opening cinematic, he was not introduced as a character and given a name and personality until Heroes of the Storm.