Look on Youtube and type in Keldeo Event. That's where I found a code for Keldeo, Melloetta, and Genosect, but I only tried the Keldeo code. They are event pkmn because the Keldeo I got was able to do the event with the other 3 fighting pkmn in the Moor of Iccirus and he learned his special Secret Sword move3. I have the codes for black, not white, but that's how I found the event code. I didn't know if it would work b/c it was written in German, but it worked for my US game. Also, the Keldeo I found is sadly named 'bob' but I found a code where you can change traded pkmn names!! Just search around Youtube that's where I found working event pkmn codes.