Like its prior forms, Aurostice seems to be directly based on a yuki-onna, a yōkai from Japanese folklore.
Statistically, she is a potent special attacker with high power and above-average speed. Although, defensively, she only has one resistance to herself, and her defensive stats are lacking as well. Nevertheless, her early availability and Ice-type moves make her a solid choice for a team member. In Deneb, Aurostice will be one of the best Ice and Fairy Pokémon since the devs blessed her evolutionary line with the rare Pixilate ability, replacing Inner Focus.
Be sure to give Frozaiden an Everstone until she reaches level 35, as Aurostice cannot learn Ice Beam through any other method.