The evolution system in Pokémon Mystery Dungeon games works differently than the main series. Pokémon do not evolve through leveling up. Instead, you can only get certain evolutions through:
* Finding evolved forms in the dungeon: You might find a Blastoise already living in a dungeon.
* Using a specific item: Certain items, like the Shiny Stone, can trigger evolutions for specific Pokémon.
* Completing certain tasks: In some cases, like with Squirtle in the original Mystery Dungeon games, you may need to complete a specific task (like winning the Mystery Dungeon Tournament) to get its evolution.
Unfortunately, Wartortle does not have any known evolution methods in Blue Rescue Team.