What will happen if you receive and use a hacked pokemon?

Admitting to it on the official forums might remedy that.

Pede poena claudo.

It is not a case of being caught every time, though obviously that would severely discourage hacking. It is a case of increased exposure to official systems increases the risk of a ban.

The more you do it, the more likely you are to get caught.

I don't personally care if people want to manipulate their single player games. It doesn't hurt anyone else. But cheating cheapens competition and these are Gamefreak's servers or events, so Gamefreak's rules.

No, off to the Nintendo mines with you, child. They'll have you chained to a rock digging for polygons inside a week.

I can feel the massive wario face coming nearer And nearer!

noooooooooooo!