Following the Nebuchadnezzar's near-destruction, Morpheus recruited new crew members from the ship, the Enki, among them Phoenix.  Phoenix was the rough equivalent to replace Mouse, who was killed by the Agents' soldiers.  Phoenix had programming skills as well as fighting skills within the Matrix.

It is unknown where Phoenix derived his nom-de-hack, but it may be due to his resemblance of Wesley Snipes' character Simon Phoenix in Demolition Man.  He has light-colored hair and dark skin, and tends to wear armor resembling that worn by Snipes in the movie.

Phoenix became a good friend of Nil Excess, a hacker whom the Neb recruited.  He supported Nil during his crisis following his meeting with the Oracle, and even assisted Nil when the hacker tried to contact his estranged brother Gregory.

When Nil was sent into a coma following his final confrontation with Agent Green, Phoenix was very concerned for his well-being and took steps to defend Nil's honor when fellow crewmate Artemis suspected Nil of having Agent sympathies.