Like Link and Zelda, Impa has multiple weapons. This video shows her using a naginata, a pole with a blade on the end. Choosing the naginata gives Impa flashy spin combos and fire attacks. It looks like she can shoot a blast straightforward too which was useful when fighting a Tektite.
Hyrule Warriors comes out on August 14 in Japan, September 19 in Europe, and September 26 in North America.