Did you wonder why Black Kyurem and White Kyurem - the cover stars of Pokemon Black and White 2 - look like Reshiram and Zekrom. All is explained in the latest Pokemon movie trailer.
At the beginning of the trailer we see the original Kyurem - the one you may have caught in Pokemon Black and White - absorbing energy from Reshiram and Zekrom.
According to the official Pokemon movie website, Kyurem absorbs Reshiram and Zekrom's genes to become Black Kyurem or White Kyurem. These are two new Legendary Pokemon but other than the fact that they have Reshiram and Zekrom's genes we know very little about them. Their Types and moves have yet to be officially revealed.
As for the movie itself, Kyurem - the strongest dragon on earth - attacks Ash and crew when they were on their way to rescue Keldeo.
[ Source: Pokebeach ]