Can't get how Fairy can be super effective against Ice so I have new thoughts now. either there are two new types to be introduced or....
1. Fairy isn't the new type, we aren't getting it this gen.
2. Divine/magic or Holy creatures fit more, they can melt ice with their light maybe.. and Sylveon was shown to not be a fighter in Pokemon Smash and was knocked out easily, Divine creatures aren't really good at martial arts..
3. Sylveon is dual typed, but rock/grass just doesn't fit the look.
4. now here, I'm not joking, It's Love type, Sylveon isn't a fighter, her warm love can break ice, and obviously lovers hate for their love to be poisoned, (and it could at least fit with the new bond system X/Y are supposed to introduce)