~Magic
It doesn't "come" from anywhere. It simply is. Like any force of nature, it's wild, unpredictable, untamable. It still can be used, though. Many people in this world have learned to tap into it, to harness it. Unlike other forces of nature, though, it can be anything and anywhere - you just need to reach out to it and take hold, and when you do you can do anything. Cast any spell and move any rock.
Some people say Magic is also alive. Many believe spells are almost like a prayer, whispering to this invisible tempest to let its power flow through them, though this is mostly considered nothing but a myth. Still, it's undeniable, that palpable tension in a deep enchanted wood or a well of precious minerals that something in the air is vibrating. Radiating. Concentrating. Even if you don't believe that Magic is a living force, you know it's certainly no dormant one either.
And if some spells may be a prayer, perhaps other spells may be commands - words that compel this unknowable force, hoist it from its limbs and shove it into place. A curse or a hex wouldn't be something natural for Magic to be used in this world. Turning someone into a beast or a monster is something Magic was never meant to do. If it were a living force of nature, it would enact its own revenge, for using Magic in such volatile fashion will always have a consequence. And something as ancient would have a very long memory.
But again, it is nothing but a myth. Right?