How do you use rank up magic limited barian force card?

Answer 1

To use Rank-Up-Magic Barian Force, you select the Xyz Monster on your field that will be used as an Xyz Material for a Xyz Monster 1 Rank higher than it from your Extra Deck (Must be a "Number C" or "CXyz" that will be Summoned and must have the same type as the monster on the field). Place that Xyz Monster on top of the selected Xyz Monster on the field and any remaining Xyz Materials on the original monster will be added to the new monster. Then the last effect of Barian Force will resolve and take a Xyz Material from your opponent's monster and use it as its own.