Mila is the third wizard you face off with in The Arena.
"Mila didn't get her outfit from the Academy... in fact, she came here dressed like this. She's been casting spells for years, and uses all of them to defeat challengers."
Mila wears the Prankster's Crown hat and an unknown outfit. She also holds the Ivory Star wand. This gives her a heart bonus of at least 40 and a damage bonus of 20.