The Disciple is somewhat of a mystery. In his first appearance, it is shown that he protects the Dead Zone.
His first appearance was Spawn #150 when Spawn returned to the dead zone (a land of Heaven's territory), after some monologue-ing....they begin to fight and within a few seconds, Disciple rips Spawn's brain out and throws his him body back to Hell
whilst throwing his heart to the green world,
He later has a brief cameo in #158 but is not seen fully untill #160, than it was revealed that this Disciple was one of Twelve...These warriors were made from the souls of the twelve disciples of Christ and James was the weakest of them.