Things You'll Need
Instructions
Go to Castelia City in "Black" or "White." Travel to the northern road, which leads to Route 4, and enter the building on the left.
Talk to the scientist on the second floor by pressing the "A" button and tell him "Everyone Happy" and "Simple Connection." He will activate the Relocator, a special trading device.
Save your game and return to the main menu. The Relocator is now available. Highlight it with your cursor and press "A" or click on it with your stylus. It will send out a wireless signal to look for another game.
Turn on the second DS system with "SoulSilver" in it. You must have a fourth generation Celebi in your game that has never activated the "Zorua" event before. In the main menu of the DS, you will now also have access to the Relocator. Click on it.
Follow the steps the Relocator provides to trade your Celebi to the Generation V game. Add it to your party in "Black" or "White" and go to the GameFreak building in Castelia City. If you do not have at least one spare Pokeball of any type, purchase one from the nearest Pokemart.
Talk to the trainer inside, and your Celebi will come out of its Pokeball. The Pokemon next to the trainer will transform into a Zorua, as it was previously disguising itself with an illusion. Celebi and Zorua play with each other and the trainer will give Zorua to you as a gift. You need the extra Pokeball in order to hold Zorua.