It's outside the scope of the setting.
To clarify: anything magical is directly or indirectly the result of interference by Ghastly Thingummys from Beyond Time and Space ™.
A book of magic, magic artifact, etc., is always going to be, essentially, a telephone that puts you on the line with the Ghastly Thingummys.
People who are physically different from baseline humanity are either genetically descended from Thingummy-Human breeding projects of the far past, or have been directly warped and shaped by those beings, or some combination of the two.
Also, tonally speaking, this is a pretty bleak sort of thing and the exact opposite of a power fantasy.
To clarify: anything magical is directly or indirectly the result of interference by Ghastly Thingummys from Beyond Time and Space ™.
A book of magic, magic artifact, etc., is always going to be, essentially, a telephone that puts you on the line with the Ghastly Thingummys.
People who are physically different from baseline humanity are either genetically descended from Thingummy-Human breeding projects of the far past, or have been directly warped and shaped by those beings, or some combination of the two.
Also, tonally speaking, this is a pretty bleak sort of thing and the exact opposite of a power fantasy.