The students all looked a bit shocked at the news that one of them had actually willingly entered into a Servant Contract with a Demon, and from the sounds of it, she might have initiated it herself.
They hadn't seen the mark on her when she was in line, so it must have happened afterward, and they had been watching Wolfe the whole time.
"Does she really have a Servant Bond? I mean, who would do that to themselves?" One of the staff members who was still in the auditorium waiting for the students to finish so they could have their turn asked.
"Not all agreements are the same, but a lot of the Witches that I rescued from the Mundane Army this winter agreed to one. There are some benefits, like mana feeding. If you don't have a Familiar, or your Familiar is far away, the Demon can still feed you Mana, which can be used to build your aura.