Nyx

ニクス

Nyx's mother was a lowly servant in the house that Leina and Elina come from. One day, she came across a forbidden staff, Funikura, a sentient staff that granted her immeasurable magical powers - but she is unable to control it. Now, as a wandering fire mage, she is hooked on the idea of justice to the point where she goes overboard and ends up torching the homes of supposed villains. Nyx continues to fight and joins the tournament, in fear that she'll lose this power and driven by the need to crush all.
In the first season of the anime, she is shown for a few seconds at the beginning of episode 3 on a Queen's Blade broadcast using a fire spell.