Fistina's power armour affords her a great deal of mobility, durability, and strength.
The fists of her power armour also detach, capable of being launched as rockets. They can be used as direct offensive weapons, or as grappling hooks.
If her head is removed from her body, she is rendered immobile.
Her suit is weak to certain sonic frequencies, causing it to fall apart.
Prior to Death of Ben 10, Fistina was a criminal operating in Undertown. However thanks to her crush on Rook she offered to help out when the original Bellwood Plumber Base came under attack from Kundo. Her actions rewarded her with a reduced sentence and an offer of becoming a Plumber afterwards from Magister Max Tennyson.
Fistina first appeared in Chapter 6. She was recruited (alongside Liam) by Rook to help protect Sella since the Plumbers weren't officially allowed to help her. In exchange she was given a reduced sentence and Ben offered to put a good word in for her when she applies for the Plumber Academy.