Odo was the officer in charge of running the ore processing center on Terok Nor. Odo had a strong desire for order and obedience, and ran the most efficient operation in the entire Klingon-Cardassian Alliance.
Odo was killed by Julian Bashir's mirror universe counterpart, who had been forced to work in the processing center for the Alliance, during a thorium leak that disrupted the center's operations. In the subsequent evacuation, Bashir shot Odo with a phaser set to kill, destroying the changeling. (DS9: "Crossover")