This is the only way to directly edit your save file.
Nintendo employs automated telemetry. When you go online to battle or trade, their servers scan your Pokémon. online save editor pokemon
Save editing is not foolproof. If an editor writes code incorrectly, or if the file is interrupted during download/upload, your save file can become corrupted. Consequence: You could lose hundreds of hours of progress permanently. This is the only way to directly edit your save file