Mysterious Stakes

Mysterious Stakes are stakes in the ground that, once collected, unlock a member of the Ruinous Quartet’s Ruinous Shrine.
There are thirty-two stakes in total, with each member of the Quartet having eight stakes each.
When a stake is interacted with, the player has the option of pulling it out or leaving it alone. If pulled, the stake will mysteriously vanish. If all eight of the corresponding Quartet's stakes are pulled, upon the last one being pulled, the screen will shake as the player looks in the direction of the shrine the stakes were associated with, where they may return and challenge the Pokémon.