NPC Spawns

Throughout the Grand Underground, you will find a variety of NPCs to talk to. These don't really do much but do give you a variety of tips. However, there is a catch. You need to talk to 32 Unique NPCs or people in the Underground to get a Spiritomb when you have put an Odd Keystone into Route 209

This can be a daunting task but there is a logic to the spawns in the underground.

In each segment of each area (the gaps between Pokémon Hideaways), there are several places for a NPC to spawn and only one NPC will spawn at any on time. While all characters can spawn in any place, each area has got a boosted chance of spawning specific characters to help you more easily track them down..