Of cause, it works if for cartage games and there is two options: Make backup copies of your game and hack your game saves.
When I cheat, I cheat for items that are rare and hard to come by (Master Balls, rare-candy, and mega evolution stones). Here is a list of the codes that I use for Pokémon X: https://powersaves3ds.maximummemory.com/home/gamedetails/EKJE
Getting the Pokémons is easy, I just trade myself. Pokémon is one of the game series, one meant to complete with tradings between games. Part of the fun is finding out witch Pokémon is exclusive to which version and trade. Those that are exclusive from special events content can be hacked, via the power-save.