A Jem'Hadar attack ship under his command managed to sneak up on the USS Defiant, disable the vessel, board and capture the ship. Gelnon left the Defiant under the command of the Jem'Hadar Kudak'Etan while he proceeded with his main objective to raid the planet Coridan. (DS9: "One Little Ship")
Commanding a fleet Gelnon was able to break through a weak point in the Federation's lines in the Benthara system to launch an attack on Coridan. Genlon's orders were simply to cause as much damage as possible to hamper the supply of dilithium from the important world. Gelnon succeeded in his mission and bombarded the planet's surface before retreating his forces back to Dominion territory. (The Dominion War Sourcebook: The Fires of Armageddon)
- In The Dominion War Sourcebook: The Fires of Armageddon his name is misspelt "Genlon".