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Buca became part of Jovus' warpack and eventually came to serve at the old Chieftain's side. After the end of the Human-Covenant War, Jovus and his pack resorted to raiding and pillaging human military outposts.
During an assault on Braden Station, a UNSC repair and resupply facility, Jovus found the station's commanding officer and then had Buca present him to the human. Buca relayed Jovus' infamous legend but left the human unexpectedly bemused. Upon inquiring, Buca shared that the soldier had been frightened by the thought that Jovus was actually the legendary warlord, Atriox. This greatly enraged Jovus who killed the human and then commanded his pack to destroy the entire facility. When Jovus asked what had Atriox done to deserve a bigger reputation, Buca informed him of Atriox's past exploits. Wanting to test his might in a fight, Jovus ordered his crew to track down Atriox.
Once the warpack located Atriox on Karava, they arrived and encountered members of the Banished on the planet's surface. After a brief and violent clash between both sides erupted, Buca helped a wounded Jovus to his feet as they came into direct contact with Atriox himself. Atriox notified Jovus that he had no intention of killing him and revealed that some within Jovus' own pack had previously contacted him, expressing hope that they could potentially ally with the Banished. When Jovus asked who had contacted him, Buca came forward, telling Jovus that he was a great warrior who should align himself with Atriox. Although presented with the opportunity to join the Banished, Jovus instead ignored the offer and unexpectedly charged forward to attack Atriox. When Jovus was quickly struck and killed by Atriox's gravity mace, Chainbreaker, a bewildered Buca pondered why Jovus would attack knowing that he was severely outmatched and weakened. Atriox then informed Buca that the old Jiralhanae did not wish to have his life spared, as he traditionally believed that he and his warpack could only respect Atriox if he was the strongest and dominant leader. Atriox announces that he would not view strength as a threat, not when he would put to good use for the Banished. Eventually, Buca and the rest of remaining Jiralhanae of Jovus' pack then rallied to Atriox' side and joined the Banished shortly afterward.
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