They've revealed another Pokemon, and this one's a doozy.
Manaphy, the D/P cute legendary, uses its Heart Swap ability. What this does is it makes two players switch places. The example they gave on the website is player 1 is Donkey Kong, player 2 is Zelda. Manaphy uses Heart Swap, and suddenly player 1 is Zelda and player 2 is Donkey Kong. This isn't a complete swap, though: a death for Donkey Kong is a death for player 1, and the damage percentages remain as they were, only swapped over. After a short while the effect reverses itself.
Good lord. That's quite something.
For those unaware, this is Manaphy: