Player has 50 different outsider IDs
bulbapedia
-In the upstairs of the Pokémon Center, a man wearing a black suit will give the player some rare items based on how many different outsider ID numbers the player has in their possession (despite his claim it is based off the number of trades), acting as a Generation V equivalent to the Lucky Channel and its successors. These items are usually acquired by battling on the Battle Subway. If the player has not traded with enough people to receive an item, the man suggests players use the GTS