>>44804353A version I wanted to see is one that's basically a Yin Yang symbol with one side resembling Zekrom and the other resembling Reshiram.
Black Kyurem has a normal right arm, wing while the left are all made of ice. And the reverse for White Kyurem.
My theory is that the Original Dragon is more like pic related. And because Zekrom/Reshiram only makes up the right/left half of the Original Dragon, kyurem had to create the missing parts out of ice for either form.