Future!AU, in which Jack barters with Pitch to find a way back home and unknowingly pays with a piece of his center. Pitch takes much more than that.
This would later on lead to Jack forcefully becoming mortal.
Yeah IDK, sounded like a cool concept. I thought Jack’s center would be in the shape of a hexagon. (North’s could be a cube, Sandy’s a sphere, Tooth a diamond and Bunny’s a pyramid. These are all based on the shapes from the art book.)