Is it really necessary to make a sequel instead of a third game?
Does this mean the Gym Leaders and E4 will be different?
Maybe N will be in an undiscovered area and be a secondary Champion like Red in HG/SS. Team Plasma may return in these games and the Six Sages may play a bigger role in the games (battle-able executives).
We can assume that Kyurem's formes will have attacks corresponding to the corresponding Tao Pokemon pair. But does this mean Kyurem must fuse with or just borrow energy from Zekrom or Reshiram?
Battle Frontier, anyone?