[Well, she stops, and sets herself in a wary stance, a little surprised for a half second, and then she steps forward and folds her arms.]

Because you took some of my fire and were going to do something that could hurt one of my friends. And you didn't offer anything in trade for it, you just took it. That's not nice.

[She's well aware of the nature of flame, and this spirit seems as mercurial.]

We can burn things, absolutely. But aren't you mindful of the other spirits and what they want too?