Shaymin can be captured by owning Gracidea. You can obtain the Gracidea by going to route 9 and talking to the lady in the building before route 10. After you talk to her you need to have all 5 colors of any evolution of Floette. When you get all five colors go talk to the lady again. She will give you the Gracidea. To catch Shaymin you need to head to Cragonos Cliffs and head down the path to find a hill with flowers on it Shaymin will be there. Warning: Shaymin is a one time encounter. Saving before battling is recommended. To evolve it into Sky Form, use the Gracidea to change Shaymin to it's Sky Form
If you kill it then you can be patient and find it in the wild.
Level Up Edit
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