UPDATE: To clarify some of the confusion, Black Kyurem and White Kyurem are the actual alternate formes of Kyurem. “Overdrive mode” has yet to be fully explained, but we’re guessing it’s probably a circumstantial variation triggered by Kyurem getting “emotionally worked up” — perhaps a stat boost when it has low HP or PP? Perhaps a visual indicator that it’s ready to use its signature moves? We’ll have to wait and see.
Pokémon Black 2 and White 2 revealed that Kyurem had alternate formes just as Giratina did before it, but when we got our first look last week at the sequels’ box arts, they looked… different.
That’s because the alternate formes have alternate formes, the Daisuki Club website confirms. When Kyurem takes on Zekrom’s or Reshiram’s DNA, it becomes either Black Kyurem or White Kyurem, respectively. When those new formes are emotionally worked up, they go into an “overdrive” mode and become Sparkling Blue Black Kyurem and Burning Red White Kyurem.
This certainly complicates fans speculation that the box arts appear to have a ruby/sapphire behind the logos, possibly suggesting Hoenn as an additional region in the game. Personally, I just want to know if the new formes do indeed have a tertiary type!