Ari was a male Cardassian soldier in the 24th century Cardassian Union until his death in 2371. However, he opposed the seemingly limitless authority of the Central Command and the Obsidian Order, and so became part of the Cardassian dissident movement.
When Ghemor's apparent daughter, Iliana Ghemor (really Kira Nerys) came under increasing danger through interrogation from Order operative Corbin Entek, Ghemor asked Ari to help her escape Cardassia. However, Entek surprised them, as it was a plot to expose Ghemor as a traitor. Ari made a move to attack, but Entek quickly killed him with a phaser. (DS9: "Second Skin")