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The Spear Key is a special artifact in the anime that is currently under the possession of Team Galactic. Nothing is known about its origin or purpose.
In Journey To The Unown!, Saturn and two Team Galactic Grunts head inside the Solaceon Ruins. In an inner chamber, they place the Splash Plate, Draco Plate and Iron Plate into slots on the floor which releases the Spear Key in the form of a cube.
Later in Enter Galactic!, Saturn and more grunts arrive at the site of the meteorites in Veilstone City so that the power of the meteorites activates the Spear Key.
In DP097, the Spear Key is used by Jupiter to locate the Lustrous Orb. As the episode ends, the Spear Key, along with the Adamant and Lustrous Orbs were seen attached to machines in Team Galactic's base.
Three plates release it...
- A picture on the TV Tokyo Pokémon website shows what is apparently the Spear Key inside what appears to be a portal to the Distortion World, surrounded by the members of the lake trio, indicating a possible plot point which may or may not involve Giratina and the twelfth movie.
- Its name is a very obvious reference to Spear Pillar, indicating that the two share a connection.
- The three plates used refer to Dialga and Palkia; the Draco plate to both of them, the Splash plate to Palkia's other type, and the Iron plates to Dialga's other type.
- The fact that it required three plates to release it from the Solaceon Ruins indicates its possible connection to Arceus, who uses the plates to change type.