How does smeargle learn lunar dance?

[Masked]

Can cresselia use lunar dance and survive if it's behind a sub?

 

[Arseus]

Lull Cresselia to Sleep, then on the next turn, have it use Lunar Dance, and Smeargle use Sketch (make sure Cressy is faster). IIRC, Smeargle should Sketch Lunar Dance, even though it wasn't used. This works with moves like Explosion as well.

Please, for questions like this use this thread in the future.