The Odd Keystone is an item that makes you able to get Spiritomb. It can be obtained in a number of ways. It can be obtained by a karate man in Route 208; or hidden in the pond of Twinleaf Town. It can also be found underground. The Odd Keystone can repair the Hallowed Tower on Route 209.
In the anime[]
In the past[]
500 years in the past, a Spiritomb was causing a havoc in a peaceful village in the Sinnoh Region, greatly terrifying the villagers and destroying their livelihoods. Until one day, a wandering man with his Pikachu came by and went to combat the havoc causing Pokémon on behalf of the villagers. In the end, Spiritomb was defeated and the Odd-Keystone was sealed away in a stone-hallowed tower.
Pokémon the Series: Diamond and Pearl[]
The Odd-Keystone made its debut in The Keystone Pops! when a redirected Sonic Boom from Buizel accidentally knocked down a stone-hallowed tower during a practice battle with Aipom. When lightning struck the tower, it awoke the slumbering Spiritomb.
Pokémon Journeys[]
An additional Keystone was located on a Ghost Train heading to Stow-on-Side. Goh's Grookey accidentally knocked the Keystone off the pedestal and one of the souls inside found its way into Ash's body, causing him to cruelly target Goh with its madness.