Mirror would see murky, unspeakable darkness, surrounded by awful cold. An incredible tolerance for pain displayed by ending up in pain quite often. And there was a boy... A very powerful boy.
Fever, however, jumped as soon as Mirror began to shift, Nearly tripping over himself, he bolted to the left, wrapping his scarf tightly around his face. That was something completely new that Mirror displayed, and he was very unprepared.
Throw up. It might not have the fullest effect on Mirror, who had just arrived, but Oni would soon recall what he had eaten last.