Change the lines commented out (starting at free_space ending at evos_per_entry ... Open the defines.h file in the src folder and change DEX_POKES define to how many pokemon seen in dex you want Open ...
Plus, using the Nintendo Game Boy Advance Wireless Adapter, you can trade and battle wire-free with other players. Or you can use the Game Link Cable to trade and battle with Pokémon Emerald ...