"I like those kinds of people," Buffy tells him with a fond smile. She's glad that Derek has found someone to protect, someone he cares about and while she doesn't know Katniss well, she does seem like she needs someone to help her, maybe not protect her, but to help her in some way. Sometimes, she wishes she were more like Derek and Alcide. She doesn't need someone to protect, as in an individual, but she does need to be able to help, to protect a group at large. This place gives her plenty of opportunity to do that, but not very many successes in that. Buffy needs people that care about her, and that she cares about, to be strong, to remind her that there's a good reason to fight even when it doesn't seem like it. Derek is one of those people for her.

Her concern doesn't go away as Derek explains it. Her focus just switches from overall side effects of this switch, to concern for Derek. "Yeah, definitely don't do that thing." She says it in a stern voice, brows a bit drawn together. She doesn't want him to get hurt nor does she want him to hurt someone else. She can imagine how that would hurt Derek.

She reaches out to touch his arm. "Don't be silly, Doofus. I was never worried about being safe with you." And that much is true. It's not because she doesn't think Derek could hurt her (he probably could) but because he knows he wouldn't.