Diagur Leyva was a member of the Byz Lats gang. He became their leader after the Strike Team took down Garza. Diagur made an alliance with Detective Vic Mackey, but was eventually killed by Margos Dezerian.
Before Season 3Edit
Diagur was at an arcade place with his Byz Lats friends when Detective Vic Mackey and the Strike Team arrived. Knowing about his father's involvement with the ammunition van, Vic started questioning Diagur about his reasons to buy weapons. Diagur told him they were doing what they had to do, but Vic threatened them if he found out they were arming themselves for a gang war.
Some time later, Garza asked Diagur to deliver a payment to Lonzo Wang, who had called them claiming he had a new shipment of drugs. Diagur arrived at the park, but when he was about to hand the money to Tavon Garris, he told Diagur to hold the money for awhile. As he drove away with the money and the drugs, Vic, Lem and Ronnie stopped him and brought him to a hotel room. There, Vic offered him the chance to become the leader of the Byz Lats if he helped them bring down Garza. However, Diagur refused to.
Some time later, Ronnie brought Kern Little to the hotel room. Vic then gave them a map of Farmington and told them to redistribute the neighborhood equally for each gang. Both of them were reluctant to deal with each other, but Vic convinced them and left them with Lem as he went to the Barn to check something. While he was gone, Kern and Diagur were unable to reach an agreement. When Vic returned, Diagur told him that they wouldn't be able to do it. Vic dragged Diagur to the bathroom and tried to convince him by telling him that Garza would surely end up in jail. As Vic pressed on him, Diagur confessed that Garza had given Esteban a gun and a map to find Calva.Vic then convinced Diagur to go to Garza's house to deliver the package and signal them as he walked out to let them know Garza was in. After leaving the bag of drugs in the house, Diagur walked out and turned his cap backwards to signal Dutch Wagenbach and the Strike Team. They then went in and arrested Garza.
Diagur replaced former leader Garza when the Strike Team took him down. Diagur allied himself with Mackey, but was murdered (his feet chopped off) by the Armenian Might, most likely by Armenian hitman Margos Dezerian (who has a foot fetish), when they connected Diagur, through Vic, to the Money Train robbery.
After the deaths of Diagur and others, whom the Armenian mafia suspected of robbing their Money Train, Mackey and the Strike Team agreed that Dezerian must be put down before he targets the Strike Team. Using false information, Mackey managed to track down Dezerian and shot him twice in the chest, killing him and avenging Diagur's death.