In Dresden files, say you have a Changeling with Seelie Magic. The Changeling has a positive refresh, and thus has free will.
If the changeling uses Seelie Magic to kill another mortal, have they broken the first Law of Magic, and thus gain the Lawbreaker [1st] stunt? Or does this not apply to the Changeling? What about other kinds of Sponsored magic?
There are two things to consider:
YS182.This view is enforced in the text on YS232, i.e.
You could say that the Laws exist as two separate concepts with 99% overlap—the Wardens of the White Council enforce one concept (law), while reality metaphysically enforces the other (nature).
The first one is pretty well set out in terms of targets on YS232, i.e.
The White Council has made clear that their Laws don’t apply to entities that aren’t people. The Laws of Magic are strongly oriented on protecting the lives and rights of mortals. Creatures and folks that the Council might classify as “monsters” are fair game. With that said, this is a rule of thumb where it’s easy to stumble into the grey area, with things open to interpretation by the Warden on the scene—and given that Wardens have a lot of latitude regarding the whole “judge, jury, and executioner” bit, it’s a grey area that you want to avoid stepping into as a spellcaster.
This doesn't seem to indicate casters, but in truth, I think it does. It falls into that 'grey area' mentioned in terms of targets, i.e. if it is possible that the Seelie Court (or Sponsor) will step in to take exception to their subject having their head removed from their shoulders and it can be proven to be so (Marked by Power, anyone?), then that will give Wardens pause. Then again, if the Laws of Magic don't apply as a caster- they also don't apply as a target, making the caster a valid target outside of White Council influence under the case of 'aggressive self-defense' or somesuch.
In terms of the second part, it becomes even grayer, but I think it can be solved with a judicious look at aspects. If the changeling has not made the choice, they count as mortal for purposes of the game. The same with Sponsored magic users. So I'd think that the rules part would apply in both of those cases.
Again looking at YS232:
Whenever you choose to break one of the Laws of Magic, you’re crossing a very real line. By taking such an action, you’ve altered your self-image and your beliefs—the very basis of you—to be the sort of person who breaks that Law.
Though this is flavor text, it does point to the view that its based upon what the psyche of the character identifies as - mortal or not.
Now, if the mage is an Emissary of Power because he's explicitly not mortal, that's a different story. A lesser demi-god of some long lost power is decidedly not going to have the same worldview as the mortal emissary of the same.
From the Source Books, Dresden Files Fiction View Point: (Some Mild Spoilers from the Books to Follow)
The Laws of Magic only apply to Mortal Practitioners, i.e. people who draw energy from the world around them and from within themselves, not from a source. That said, those who do both: draw Magic from within themselves & use a sponsor ARE under the Laws of the White Council (Necromancers, etc...)
A Changeling is under the purview of the Seelie or Unseelie court. Their magic is not "Mortal" and isn't policed by the White Council. Another added benefit for using Faerie Magic is that it isn't conflicted by coming from a Mortal source and thus they don't have to worry about it hexing things either. All that said, every use of energy that comes from the wellspring of either the Winter or Summer Court IS a representation of power of the Queens, and as such is policed by the Queens (usually the Ladies) or their Sidhe Nobles. Above and beyond that, the sponsor will not grant power for applications that are outside their exact realm of influence. Essentially, if you want to use a sponsored magic for something that is outside the realm of effect of the sponsor, the magic either doesn't work or is greatly reduced.
In the book Summer Knight, Harry is working as an Emissary of Winter and as such puts himself in opposition to Summer, thus Summer Magic works against him the whole book, but when Murphy get's involved in a conflict the power of Summer is greatly reduced against her because she was not connected to either court.
Another instance is in the book Cold Days where Harry temporarily violates the "Law of Winter" and thereby temporarily looses his connection to the Mantel of Power he has from Winter at that time.
Now, does this mean that the White Council won't seek to oppose a Faerie Bound Changeling that is murdering people with Unseelie Magic? No, of course not, but the grievance between the combatants would be governed under the Unseelie Accords and not a by-law within one of the signatories (The White Council in this case). In the book White Night, Harry and Ramirez demand a duel with one of the signatories of the Accords for retribution based on murders the citizens of that signatory perpetrated on some mortal minor practitioners. In that case a formal Duel was offered and fought, but the signatory also had the "right" to pay a weregild to the White Council for killing the entities under their jurisdiction.
If it helps, think of Mortals and "Other Things" as citizens of different countries and beholden to the laws of their home nation. Thus fighting between the citizens of the nations can be legally difficult to sort out as what is against the law in one nation isn't against the laws of a different nation. This is also the sort of stuff that causes wars, as seen in Book Three: Grave Peril where Harry kicks off a War between the White Council and the Red Court of Vampires.