Magic Paradox

Each leaf of the clover represents a virtue. The first three are for Hope, Faith and Charity. The fourth is for Luck. And when a Grimoire has a fifth, it represents the Demon. However, in an old legend forgotten by all, it said that a 6-leaf exists. It would represent the Absolute Zero... or just God himself.
Why would a God coexist with a Demon? What power is the 6-leaf Grimoire?
Why would a young Peasant, moreover a "magicless" own it? Absurd, isn't it? Well not totally...

(Since some people don't read tags, this story is about Asta x Leo.)

(Previous name : Human ? Demon ? God ?)

It's not original, I know, but hey, the idea came so here's :)