However, the enormous creature’s assault soon came to an end. A terrifyingly large explosion consumed it, blowing away the blackened buildings and creating an updraft that lifted clouds of dust and debris into the air. An explosion that massive should have created a huge amount of light and sound, but the area around the three of them was more or less untouched.

“Uhh...I’m pretty sure I’ve seen one of those in a textbook before,” Mari said, dumbfounded. “That’s a mushroom cloud.”

“I don’t really know what it is, but I killed the stuff that looked like it was going to hurt us,” Yogiri said offhandedly.

...

“If I die, will you take them back to the real world?”

“I could, but the moment you die, the heat and radiation in this place will kill them instantly. I can’t do anything about that.”

-Volume 11 pages 209 and 210