Well I hope it's what I think it's referencing. Can't remember the name of the story, but the MC can only use Fireball and basically went into a "what is a ball but a sphere? And what is a sphere except an infinite number of circles in 3D Space? So what would an infinite number of spheres Ina 4D space mean? And made basically an Infinity Fireball that generates an unlimited amount of mana or something.