Pokepuff almost sounds like the "Erika's Perfume" card from Gym heroes, which was used to combo with Dark Hypno's "Bench Manipulation" attack, back when Wizards of the Coast held the rights to the Pokemon cards.
However, Erika's Perfume only let you choose one basic Pokemon in your opponents hand, not as many as you like, so that's a huge change right there.
It was an extremely gimmicky deck, and didn't see much play at all, but hey it was a fun concept.
How a pokepuff deck could be used is with the Empoleon card with Diving draw, and sky field stadium, in Expanded, or one of the Rayquaza ex cards. (can't remember which one), but it was one in Roaring skies.
and I'm pretty sure you can use this card to bench your opponents Shaymin EX they might have in their hand, and the ability wouldn't take affect. Same goes for other EX cards that you don't use to attack with, but have an ability that only activates if put on the bench like Hoopa and Jirachi.