Anna’s ice form is so cold, that it actually starts to freeze Han’s sword as it gets closer to her hand. I never knew why it broke but now I do. It’s so beautiful and terrifying at the same time. Which would make sense why Elsa could touch her because with her powers the cold/ice wouldn’t bother her. But if anyone else touched Anna her frozen form might have hurt them. that means Elsa went from being the only person who couldn’t touch Anna to the only person who could.