Replica Program

The Replica Program was a planned series of experiments conducted by Vexen under Xemnas's orders, with the appartant help of Naminé. He attempted to make Replicas of Sora in the event that the original Sora proved to be useless to his plans for Kingdom Hearts. However, after the downfall of Xion ("No. i") and her subsequent demise by Roxas, Xemnas discontinued the program. In the Secret Reports it mentions another inferior numberless replica that was taken to Castle Oblivion implying that Riku Replica also came from this program.