Medusa turned to face him more fully, crossing her arms before her chest and evaluating him.

"You want to make a deal with a Witch? You are indeed foolhardy aren't you?" She smirked. "I'll admit you have skills, but why should I trust you? What guarantee have I that you won't turn on me to save your own skin?"

Because that's precisely what she could, and most likely would, do to him.