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, and upon defeat they relinquish a Lost Illusion and a synthesis Recipe that allows the Moogles to craft a replica of the member's signature weapon. Defeating a member's Absent Silhouette also allows Sora to challenge their Replica Data at the Garden of Assemblage.
Whenever Sora challenges an Absent Silhouette to a battle, the Absent Silhouette takes the form of the slain member it represents and fights him. The Absent Silhouette initially appears as a dark sphere depicting a silhouette of the slain member's weapon, with threads of nothingness and the respective member's element circling around it. When Sora accepts its challenge, it warps Sora, Donald, and Goofy to the location that its member was defeated. There, it challenges them to an arduous battle.
Though they serve as rematches with bosses from Kingdom Hearts: Chain of Memories, each Absent Silhouette has a vastly different fighting style than in the previous game. For example, in Kingdom Hearts: Chain of Memories, Larxene throws her Foudre and Zexion uses his Book of Retribution to create doppelgangers of himself using skills stolen from his opponent, while in Kingdom Hearts II Final Mix, Larxene's Absent Silhouette creates clones of herself for speedy attacks from multiple directions and Zexion's Absent Silhouette uses the Book of Retribution to trap his prey in a pocket dimension.
In Kingdom Hearts Birth by Sleep and Kingdom Hearts Birth by Sleep Final Mix, the Vanitas Remnant and the Battle Mission Unversed appear throughout the worlds. Like the Absent Silhouettes, the Vanitas Remnant initially appears as a dark sphere depicting the Keychain of the Void Gear, and the Battle Mission Unversed appear as dark spheres depicting the Unversed emblem. However, the spheres are only surrounded by wisps of darkness, without any threads of nothingness.
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