Human Catapult

The explosion was not so big, but big enough that it rattled the whole classroom building. Already half-broken window panes and weak concrete walls shattered due to concentrated explosion waves such that everything inside was shook together. 

Smoke and dust filled the room, while Frank outside narrowed his eyes. There was no alert of him winning the game, which means that the white mask guy inside was either unaffected by the attack or managed to stay alive at least with serious wounds. But in any case, it made him wary. 

"Hehe, You survived? Come out and greet your father, then?"

Inside the destroyed classroom, Crey was lying on the wreckage of broken benches. His body was covered with blood and burns, ears ringing from the sound of the explosion. That's why he was not able to understand what was being screamed by Frank outside.