Pretty much the only other thing I can come up with is to use Spawn of Psyduck and edit Pokemon so that they don't spawn in any biome. This would be a very long process, and you would have to set up a spawner for every Pokemon you want to spawn in the game.
Pretty much the only other thing I can come up with is to use Spawn of Psyduck and edit Pokemon so that they don't spawn in any biome. This would be a very long process, and you would have to set up a spawner for every Pokemon you want to spawn in the game.