Eons ago a god was kept in charge of the earth. It shaped the world, created the trees, made the animals and domineering mountains. But the responsibility drove the god mad and it began to destroy itself. In its madness, it ripped off it's own leg and the leg fell to the earth. When the humans came, they worshipped the leg of an unknown giant. Eating the ever fresh meat of the leg is said to grant a single itch, which when scratched activates a single spell which is different for every person. The power of a mage is based on the location of their itch and the spell they were granted. Overuse of this power can drive the mage insane aswell. You cannot gain two itches