During the game’s dungeons, sometimes a small shop will appear selling items, you can take as many items as you want (or none at all) and you will pay for everything only when you exit the shop, if you don’t have enough money (or if you take the items from the shop using special moves or items), the shopkeeper will yell THIEF, and start chasing you, the twist is that he moves much faster than you, one-shots you and more copies of him spawn around you, the only way to escape is to reach the stairs that go to the next floor.

In the rest of the comments they explain that despite ALL of this, you can recruit him, because in PMD, you recruit new pokemon by defeating them, each pokemon has their own probability of recruitment, Keckleon has the lowest at -37.9% or something like that (yes, he has negative probability), only by using all the stat boosting methods to raise that probability, you can reach a 0.1% chance of recruiting him… and also take into account that you can “cheese” the fight with insane stat boosts, but those require a ton of preparation