"Here's your mania," the ginger-haired kid said, holding up a marble. "Your mania is this cat's eye. Specifically this one." Fingers flick open, the glass sphere with the blue & yellow streamer in it falls, collides with a school of like orbs of like color, scatters them violently within the confines of the stone-age binding circle. "Now it's in play with all these lookalikes. The thing people think is you, your habits, your ideas, your pursuits, whether you go to the movie theater on days threatening rain or not, that stuff? Your mania," and the kid points, "is irrelevant. All it's going to do is collide and conflict, co-ordinate and complement. You might as well not play."
"Lucky for you I don't want to," his flouncy-haired sibling said, and kicked him in the nose.