I know that you are allowed only one challenge of each type in a challenge phase, but can you kneel multiple characters to challenge two different opponents simultaneously?
Example:
I have Khal Drogo and Drogon in play. I have two other opponents in a melee game, player A and player B. Neither player A nor player B have any characters on the board, but they both have power tokens on their House cards, so are ripe for a Power challenge. Can I, during my Challenge phase, kneel Khal Drogo to Power challenge player A, and simultaneously kneel Drogon to Power challenge player B? We then resolve the challenges one at a time, and assuming I'm successful in both challenges, I move power from both Player A and B onto my house card.
Is this allowed?