In Black 2 you will get Latios. In White 2 you will get Latias. Go to the Dreamyard and go to following places in order:

1.Entrance
2.Between Oil can and wall
3.Use cut on the tree and go forward and up the stairs
4. Make a left and go down
4 1/2. Save the game
5 Go to the other side, on the edge, avoiding going down the stairs
If u exit the Dreamyard, you will need to start the process again. If u run away from Latios/Latias, turn off the system and continue saved game explained on step 4 1/2. Repeat step 5.

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