Ari was a Cardassian soldier who served until his death in 2371.
He was an aide or other form of associate to Legate Tekeny Ghemor, and a member of Cardassia's dissident movement opposing the seemingly limitless authority of the Central Command and the Obsidian Order. Fiercely loyal to Legate Ghemor, he was killed by Entek, an Obsidian Order operative attempting to expose Ghemor as a traitor. (DS9: "Second Skin")
Ari was played by Billy Burke in his first television acting role and his only Star Trek appearance.
The script for "Second Skin" states the pronunciation of Ari's name as "ARE-ee." Additionally, it describes him as "a young Cardassian soldier, barely out of his teens"