Fistina is a former villain in Ben 10 Omniverse. She is an Acrosian from an unknown planet. She wears a high tech battle suit with a removeable fist.
In The More Things Change: Part 1, Fistina, Liam and Bubble Helmet come into Mr. Baumann's shop, but Bubble Helmet got into a fight with Cannonbolt. Fistina and Liam set the bomb on the floor but they were caught by Rook. After the bomb exploded, they escaped to Undertown.
In The More Things Change: Part 2, they returned to their base and were defeated along with Psyphon.
In Special Delivery, a date with Fistina was sold for one Tayden by Psyphon to Loovis Slerdlerk.
In Rules of Engagement, she helped Ben to defeat Looma Red Wind. Having already been captured by Ben and Rook earlier in the episode she was in their custody when they confronted Looma Red wind who was rampaging in Bellwood and Undertown kidnapping people as part of her engagement to Ben. While defending the KraahoRook is kidnapped as well and Fistina aids Ben in finding them, as they also have one of her fists she can track them, in order to rescue Rook the object of her affections.
In The Ultimate Heist, she was seen working for Argit along with Solid Plugg. She and Solid Plugg got into Inspector 13's warehouse and they defeated the Techadon Robots inside. However, like the others, she was tricked by Albedo and got tied up by his Wildvine’s vines. While they were tied up she flirted with Solid Plugg.
In No Honor Among Bros, she and Fistrick escaped from the Plumber HQ in order to participate at the Golden Fist Tournament. She was defeated by Fistrick in the semi-finals. At the lobby she knocked out the guards and stole the Golden Fist. However, before she could have caused any harm she handed over the fist to Rook, because of her crush on him she won't hurt Rook.
In Universe vs. Tennyson, she was freed from her cell by Chadzmuth. Later she was recaptured by Terraspin but was freed again.
In The Final Countdown, Fistina was already in custody when Kundo took over the Plumber Headquartersseeking revenge on his former pupil Rook Blonko whom was working the graveyard shift in HQ at the time. In order to undo the lock down cutting the Plumbers off from each other Rook, with a great deal of reluctance and on Robucket's insistence, Rook deputizes Fistina and her aid soon proves to be invaluable in regaining control of the base. Once the situation is resolved Max Tennyson states that after she serves her time she can apply to the Plumbers' Academy.
In The Most Dangerous Game Show, Fistina is among the many females chosen to compete for Ben's hand in marriage, but is subsequently eliminated.