Who is she?

"Himari. If a noble orders you to do something you gotta obey. If you don't accept, you are automatically accepting a duel. " Nagi explained

You see, now Nagi was more worried than embarrassed. Amaterasu Nakata, son of Baron Nakata, probably the best student in the entire first year class. An incredible able Mage. 

Nagi knew that Himari was a Mage of the end, but she didn't even know what they were... she was going to get crushed.

"Ok, I accept the duel. If I win, you and all of your "Friends" will leave me and Nagi alone. If you win I will do what you requested."

Amaterasu was slightly shocked she accepted but "O-ok tommorrow at -"

"Oh no, we are doing this think now." Amaterasu was even more shocked now "Or are you too scared" Himare grinned.

"Here in the corridor? Are you out of your mind?" Nagi screamed.

"Everybody, get out of the way!" Himari screamed "Unless you wanna get hurt!"

After everybody had moved sufficiently out of the way. Himari pointed a finger at the ground and suddenly, a huge barrier was created. It engulfed her and Amaterasu, and then turned solid. 

"Is this enough? Or should I break the walls around and expand the barrier?" Himari asked.

"NO! This is enough" Amaterasu was shaking. How could a Nobody like her create a barrier this powerful. And without chanting too!

"Are you ready?" Himari asked, grinning even more.

Amaterasu felt an emotion she had not felt in a long time. Fear. The fear to lose.