catch a nincada in the grass on the right of rustburo city easy way-if your enough through the game you can just chuck an ultra ball at it other wise just catch it the old way. leave room in your party then when nincada evolves at level 20 if you left room a shedinja will be in the empty spot of your party it will have the same moves as your ninjask it will have 1 hit point and its poke power is "wonder guard" only super effective moves hurt it.