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Here's a question that we've had come up. If Rocket's Scyther uses Shadow Images, does Misty's Staryu's Swift attack do 20 damage (no coin flip would be necessary)? Since the attack did damage then Shadow Images would no longer be in effect. Also an attack that only confused or put Rocket's Scyther asleep would not remove Shadow Images correct?

You are correct on both counts. Swift gets through Shadow Images, and you have to somehow deal damage to Scyther to remove the Images.