Pokemon Black and White 2-Now with a sexy rival.

Two new legendary "forms" look like a fan-made fusion of kyruem and the original versions legendaries.

I haven't played it in a while, but i think the storyline for kyurem was something along the lines of "reshiram + zekrom were created when kyurem was split, hence why kyurem is in a weakened state"

Like I said, I forgot exactly how it goes but reshiran + zekrom were definently derived from kyurem somehow.