Ellis Rezian was a leading figure of the Armenian Mafia.
Ellis was set up and arrested by Shane Vendrell. Even from prison, however, he is determined not to allow Diro Kesakhian to become the boss of the Armenian mob. Therefore, he teams with Shane near the end of the sixth season in order to stop Kesakhian from unleashing retribution on Vic Mackey's family. In the aftermath, however, he vowed to hold the Money Train heist over Shane's head. Rezian said that if Shane didn't do what he was told of if the Armenians received any problems from the police, he would murder Vic, Ronnie, and their families. He coldly added that he would save Shane, Mara, and their children for last.
In the seventh season, Rezian is released from prison, and falls in a trap set up between Vic Mackey and Shane Vendrell, where he is dragged into believing that the Mexicans are after him, led by Pezuela. However, this threat was fictitious and created by Vic himself. As Vic played Rezian and Pezuela against each other, making Pezuela believe that Rezian held the contents of the "box," which supposedly held information on Pezuela, and making Rezian believe that the Mexicans were targeting his gang. In a last ditch effort to remove Rezian, Mackey sets up a trap, where Shane barely slips out of. Rezian is set up to be murdered by Vic Mackey by two of Pezuela's thugs. Shane barely manages to get out of the crossfire as Rezian is ruthlessly gunned down along with some of his lieutenants. Afterwards, although realizing that the threat of the Armenian mob has been neutralized, Shane also understands that Vic and Ronnie set him up to be murdered along with Rezian as payback for the slaying of Lem.