As we have seen ellaine was a 700 year old fairy that looked 7 years old who had an intimate relationship with ban even if it was only 7 days long. Setting aside the disturbing implications of ban having interest in a girl that looks 7 years old (I presume she would have an older form as king does) I am wondering if she will ever actually somehow be ban's. It would imply her coming back to life however as far as we know that might actually be possible within nanatsuverse. Will this happen? How could it happen?