Nincada's Evolution:
* Nincada evolves into Ninjask at level 20.
* Ninjask does not evolve into Shedinja.
How to Get Shedinja:
1. Trade a Nincada to another player. It must be a level 20 Nincada, ready to evolve.
2. The player who receives the Nincada must have an empty slot in their party. This is crucial.
3. The Nincada will evolve into Ninjask, but Shedinja will be created in the empty party slot.
Key Points:
* You need two players. You can't get Shedinja by evolving a Nincada yourself.
* You can't trade a Ninjask to get a Shedinja. The evolution needs to happen in the other player's game.
* The receiving player must have a free party slot. This is how Shedinja is created.
Let me know if you have any other questions!