Does power swap reverse stat changes?

Question

Say I used a contrary shuckle and shell smashed 6 times, if I used power swap would that give me +6 attack, speed, and sp attack.

Answer 1

Yes.

That's what Power Swap does:

Power Swap switches any changes to the user's Attack stat and Special Attack stat with any changes to the target's Attack stat and Special Attack stat. The stat stage changes provided by Power Swap may be Baton Passed.

If you used Shell Smash with a Contrary Shuckle you would get a drop to your Attacks and a boost to your defenses, meaning that if you were to use Power Swap on that shuckle you would only get its Attack and SpA drops.

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