Before he knew it, in the space of three seconds, Zavier's consciousness was knocked out of his body. A gloomy darkness enveloped him on all sides. He felt like he was trapped in the bowels of the earth with no single photon whatsoever. It was perfect and complete darkness.
It was strange because even in that blackness, Zavier had perfect situational awareness. So, he could sense that he wasn't alone. He couldn't explain it, but all he knew was that he could see the middle aged creep with all his other senses. No one was present. It was just him, and the man.
Harry was very impressed. Even though he had hurriedly cast the illusion spell, still it was a bit shocking that an ordinary high school student could be able to actually resist him for three whole seconds. It was a very powerful illusion that could easily get an A-rank mage subdued in a second- perhaps maybe faster. In this construct that was his illusion space, mobility wasn't limited by any kind of law.