The Absent Silhouettes are optional boss battles found in Kingdom Hearts II Final Mix. Upon defeating each silhouette, the player will receive 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.[1] When Sora accepts its challenge, it warps Sora, Donald, and Goofy to the location that its member was defeated.[2] There, it challenges them to an arduous battle.
Though they are serve as a rematch with a boss 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.
- Vexen's Absent Silhouette is fought at the 11th Floor facsimile of The Old Mansion, and relinquishes a Lost Illusion and the Guide to Experimentation Recipe. The portal to the battle appears at The Peddler's Shop after the shop is remodeled.
- Lexaeus's Absent Silhouette is fought at the Station of Remembrance, and relinquishes a Lost Illusion and the Power Exceeding Power Recipe. The portal to the battle appears at the Sandlot after Sora defeats the Nobodies there on his second visit.
- Zexion's Absent Silhouette is fought at the 3rd Basement facsimile of Destiny Islands, and relinquishes a Lost Illusion and the Book of Shadows Recipe. The portal to the battle appears at the Cave of the Dead: Inner Chamber after Sora escapes Hades.
- Marluxia's Absent Silhouette is fought at the Station of Oblivion, and relinquishes a Lost Illusion and the Undying Flowers Recipe. The portal to the battle appears at The Beast's Room after Beast decides to join Sora in order to defeat Xaldin.
- Larxene's Absent Silhouette is fought at the Station of Remembrance, and relinquishes a Lost Illusion and the Secret Thunder Recipe. The portal to the battle appears at the Isla de Muerta: Rock Face after Sora lands at Isla de Muerta.
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. However, the sphere is only surrounded by wisps of darkness, without any threads of nothingness.