Crucial Stone )
|Buy For:||Cannot be bought|
|Sell For:||Cannot be sold|
In the games
The Odd Keystone can be obtained by a Black Belt in Route 208, from a tree where it is hidden by Twinleaf Town's pond, or in the Underground. The Odd Keystone is used to repair the Hallowed Tower on Route 209. The player must then enter the Underground and talk to other players 32 times. Upon returning to the surface and checking the Hallowed Tower, a battle with a level 25 Spiritomb will commence. The Odd Keystone is evidently the prison to which the 108 sprits comprising Spiritomb were bound as punishment for their misdeeds 500 years ago.
The Odd Keystone appears in the Sealed Ruins dungeon of Pokémon Mystery Dungeon: Explorers of Time & Explorers of Darkness and Pokémon Mystery Dungeon: Explorers of Sky. It appears at the pit of the dungeon, where it contains the boss, a level 37 Spiritomb.
In the anime
The Odd Keystone appeared in The Keystone Pops!. The Hallowed Tower is destroyed by Buizel while it and Aipom are training, causing Spiritomb to emerge from the Keystone and run amok. Ash and Pikachu are forced to battle it, and Pikachu's recharged Thunderbolt defeats it, causing it to return to the Keystone.