Assuming roxas is part of the guardian of light team , how will Sora and co bring him back. I don't think they would change Sora back to a heartless. In 3D we know that nobodies can grow hearts, so perhaps there are still more things we dont know about nobodies. And maybe roxas can come back without sora turning into a heartless. The only one I can think of is time travel but someone would still need to be reduced to a heart. (I really hope time travel is not used in kh3, it's already confusing). So any speculation on how he can return ?
Assuming roxas is part of the guardian of light team , how will Sora and co bring him back. I don't think they would change Sora back to a heartless. In 3D we know that nobodies can grow hearts, so perhaps there are still more things we dont know about nobodies. And maybe roxas can come back without sora turning into a heartless. The only one I can think of is time travel but someone would still need to be reduced to a heart. (I really hope time travel is not used in kh3, it's already confusing). So any speculation on how he can return ?