During Chapter 10 of the manga, Yuu (oxygen) has Sasha on the ropes during their fight at the school. He's slowly increased the concentration of oxygen in the air in the room to the point that any time Sasha's iron weapons strike a spark, it flares up dangerously. The high O2 levels are also making it difficult for Sasha to breathe. Outside the room, however, Mafuyu realizes what's going on. She puts cardboard boxes up against the door and sets them on fire, and then throws her kendo stick through the window set in the door. The super-oxygenated air causes the fire to expand into the room,rather vigorously.not bad for someone without anyElemental Powers.
Tomo under normal circumstances is a ditzy Ms. Fanservice who couldn't fight her way out of a paper bag. Tomo while under the thrall of the Aurum Qwaser runs on a mixture of Soma and Bad Ass-oline. Not only is she an utter juggernaut, but it's a testament to Aki Toyosaki's voice talents: switching back and forth from breathy, sweet and kind to hard, commanding and intimidating, with a couple of scenes having her actively use the dichotomy to her advantage and lure the good guys into letting their guard down.