An Absent Silhouette (アブセント・シルエット Abusento Shiruetto?) is a phantom version of one of the five Organization XIII members who were destroyed in Kingdom Hearts: Chain of Memories: Vexen, Lexaeus, Zexion, Marluxia, and Larxene. They appear in Kingdom Hearts II Final Mix as a set of optional boss battles.
In Kingdom Hearts Birth by Sleep, an Unversed named Vanitas Remnant appears in the Keyblade Graveyard after completing the Final Episode. Like the Absent Silhouettes, it initially appears as a dark sphere depicting the Keychain of the Void Gear.
A cutscene exclusive to Kingdom Hearts II Final Mix features Demyx speaking to Sora following their first battle in the Underworld. He explains that the Absent Silhouettes are shadows of existences that use the weapons of the deceased Organization XIII members as a medium. Before leaving, he suggests that Sora fight these phantoms in order to awaken his true self.
- The Absent Silhouette theme, The 13th Reflection, takes some musical cues from the theme to Marluxia's Final Form battle in Kingdom Hearts Re:Chain of Memories, Lord of the Castle.