Evolve the Ralts you traded from Yancy / Curtis.
You can also PokeTransfer or trade.
Either catch a ralts or kirlia (if you can catch one) THEN evolve a FEMALE kirlia into a gallade or for another (lazy) way you can trade for it and automatically register. Other than that to secure the answer for anyone elses questions GET THE POKEMON AND IT WILL REGISTER.
*= registers the full Pokedex entry