^The formes are not compatible but since there is the placeholder data for Kyurem, BW1 can see the regular Kyurem sprite. If they made a new ability, since there's none programmed in BW, that would be problematic.
Ophie said:For two-way transformations, they keep the HP the same. And for one-way transformations, such as Pokémon evolution, the base HP always goes up. This leads me to believe there are programming problems if a Pokémon's total base HP ever decreases in any way.
In any case, if Team Plasma gets to it first (and the villainous team rarely does), then one of two things will happen: Either they never actually catch Kyurem and just bring it around like it was a tank (such as with Mewtwo), or they catch it but lose it by it rebelling or them releasing Kyurem voluntarily (which has yet to happen, but seeing what happened with N actually getting Reshiram or Zekrom, it just might).
Ophie said:For two-way transformations, they keep the HP the same. And for one-way transformations, such as Pokémon evolution, the base HP always goes up. This leads me to believe there are programming problems if a Pokémon's total base HP ever decreases in any way.