Xion Replica is a central character in the Kingdom Hearts series, introduced in Kingdom Hearts 358/2 Days. She is a mysterious member of Organization XIII, created as a Replica from Sora's memories to absorb and duplicate his powers. Xion struggles with her identity and purpose, forming close bonds with Roxas and Axel. Her role is pivotal, as her journey and ultimate fate have significant consequences for the main storyline, especially concerning Roxas's and Sora's development.