Estal Vilar was a male Bajoran who lived in the Singha camp when he was boy. Among his friends there was Kira Nerys. When he was older, Estal supplied weapons to the Shakaar resistance cell to aid them in their fight against the occupying Cardassian forces. Estal remained in the weapons business when the Cardassians left Bajor.
In 2373, Estal was on Cardassia when the Union joined the Dominion. When the they began arresting and executing non- Dominion citizens, Estal promised them he would obtain weaponry for them. He also had himself surgically altered to appear as a Cardassian.
In late 2375, around a week after Revok betrayed Corat Damar and the Cardassian Liberation Front was crushed by the Jem'Hadar and the Breen, Kira contacted Vilar and asked him to supply herself, Damar and Elim Garak with weapons and explosives. Kira and Damar later brought Estal back to Enabran Tain's house, where Garak had discovered Estal's weapon deal with the Dominion. Concerned that Estal would break under Dominion torture and reveal their location, Kira agreed with Garak that Estal would have to be killed. Garak later did so and Mila disposed of his body. (DS9 - Prophecy and Change short story: "Face Value")