I believe Anya must be related to Marianne especially she has the photo of Lelouch. It is also possible that she will want to join Lelouch's harem. And how will the future "Harem poster" looks like? Poor Suzaku. He has Gino left
Well, Brittanians can always "borrow" Kallen and Guren by giving excuse that they will use her to exchange for Tianzi. Why will CF reject the offer if they can get Tianzi back and Tianzi is to be married off to Britiannia?