From Bulbapedia, the community-driven Pokémon encyclopedia.
The Spear Key (Japanese: やりのカギ Spear Key) is a special artifact in the anime. It is a powerful object capable of locating ancient artifacts. With the Spear Key having such effects, it was retrieved by Team Galactic who used it in their various schemes.
The Spear Key in its activated form
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 Double Team Turnover!, the Spear Key is used by Jupiter to locate the Lustrous Orb, which had been stolen by Team Rocket. As the episode ends, the Spear Key, along with the Lustrous and Adamant Orbs were seen attached to machines in Team Galactic's base.
The Spear Key is shown again in Steeling Peace of Mind! and Saving the World From Ruins! where it was used by Mars at Iron Island to scan Mt. Coronet so as to find the exact location of the Spear Pillar.
In Gateway to Ruin!, the Spear Key was used by Saturn and Charon to find some ruins in Mt. Coronet. When it was found, the Spear Key did not react to it indicating that those were the wrong ruins, and thus they retreated.
In Unlocking the Red Chain of Events!, Saturn used the key at some ruins on Mt. Coronet. The Spear Key reacted, indicating they had finally found the Spear Pillar. In Battle Finale of Legend!, Cyrus uses the key to open these ruins, revealing a staircase leading to the Spear Pillar. After Team Galactic was defeated and Dialga and Palkia returned to their dimensions, the Adamant and Lustrous Orbs were retrieved, but the Spear Key has seemingly disappeared.
- A picture on the TV Tokyo Pokémon website shows the Spear Key in its activated form inside a portal, surrounded by the lake guardians, which foreshadowed the events of Battle Finale of Legend!.
- Its name is a very obvious reference to the Spear Pillar, indicating that the two share a connection.
- The three plates used to summon the Spear Key refer to Dialga and Palkia: the Splash Plate to Palkia's Water-type, the Iron Plate to Dialga's Steel-type, and the Draco Plate to the Dragon-type that both Pokémon share.