Well. He blinks a little, not quite sure how to word this properly.

We rely on you to do so much; you have to go face to face with monsters that threaten the whole world. And I know you're built for that, but even so. Someone should worry about you.

She deserves having someone worry about her. And he worries more about her than the others because she's more human to him; her AI is so well-developed that she's become his friend. Even Striker, with whom he Drifts regularly, doesn't elicit this kind of response from him.

And you're my friend, so.