Iceman is omega level mutant if i am not wrong. He easily deafeats her. He had shown planatery level operating capacity while elsa was a small town level. Also he can't be killed. Vaporize him and he'll come back. read more
However, Mulan is an honorable kind of person, so in the case they had to fight, there surely would be a fair duel, and in that case it’s pretty certain that Elsa would win. She’d immediately freeze Mulan, transforming her into a statue of ice, and if needed, she would just have to destroy said statue and that’s it. read more
Wiz: Elsa was born with magical powers to control ice and snow, and would often use it to play with her little sister Anna. Boomstick: However, one night when they were playing and she was making ice pillars for Anna to jump from, Elsa tripped and accidentally blasted Anna, an event that nearly killed her sister. read more