Mushas during a mounted attack
Mushas were a class of combatants. Specifically, they launched an assault on Jedi Tsubaki when he was succumbing to the dark side of the Force; this occurred before Princess Misa came to his aid.
The short film "Akakiri" from Star Wars: Visions was the first appearance of the Mushas. The end credits list their designation as "Musha" (written 武者 in Japanese), which translates to "warrior".