M'zel had strong beliefs about a Jaffa's right to make the choice of freedom for himself, and feared the ever-increasing influence of the Tau'ri over the Jaffa Rebellion. He himself was once in the service of Heru'ur, and was one of the many absorbed into Apophis' army when Apophis killed Heru'ur. After Apophis' death, M'zel eventually joined the young Jaffa Rebellion.
He was present at Earth's second Alpha Site when it was attacked by the forces of Anubis. Along with a handful of Jaffa, Tok'ra and Stargate Command personnel, M'zel failed to escape through the Stargate to the Beta Site, and instead hid from Anubis' forces in the woods. He and 11 others including Major Green were rescued by Colonel Albert Reynolds of SG-3 and brought to the SGC. He was questioned by Major General George S. Hammond regarding the compromise of the secret off-world base. M'zel suggested that the Tok'ra had not been forthcoming in their information about covert operations, and insisted that they had a spy within the ranks of the System Lord Olokun. M'zel eventually led the Jaffa in withdrawing from the Alpha Site and the alliance with Earth. (SG1: "Death Knell")
When The Trust began attacking several Goa'uld planets with the symbiote poison, killing millions of Jaffa in the process, M'Zel immediately suspected the Tok'ra instead. He later joined Teal'c in confronting Zarin, a Tok'ra operative posing as a minor Goa'uld serving Ba'al, eventually fell victim to the deadly substance himself, as unlike Teal'c, he was not taking tretonin. (SG1: "Endgame")