I hope Aoi won't be mad for me stepping on his niche. I really needed to to a demon core meme.

Twins stood in front of a wierd circular construct. Len didn't understood yet purpose of this experiment Rin was so eager to try, but her ideas rarely dissapointed him. Rin, who was in charge of the experiment, seemed to be just poking around for a while. Eventually, she figured something out and a burst of bewitching yet deadly blue light illuminated them.

"Beautiful, isn't it?" Rin asked.

"Yeah, but…is this all that you wanted to show me?"

"Of cource not! The fun part will be later. Let's just sit there and wait for a while, okay?"