Favors and Fey are interesting things. For the most part it’s considered best to avoid offering or accepting a favor with the Fey. Doing so rarely ends well for any mortals involved.
Just doing something for a member of the Fey – or having a Fey do something for you – doesn’t lead to an obligation to return the gesture. If Max saved Gavin from being covered in iron, Gavin may be (grudgingly) grateful, but he wouldn’t be required to do anything in return.
For someone to be obligated to return a favor, the favor has to be explicitly offered and the recipient has to actually say they accept it.
It’s not binding otherwise. As we see above, Gavin needs to actually state he’s offering Max a favor, and Max needs to say he accepts it.
No witnesses are required to make this binding. The Fey’s magic itself recognizes the verbal contract and locks both members of the party to the terms stated.
The terms of the return favor do not need to be stated right away, though. Gavin could have held off on deciding what favor he wanted in return for a year and a day. If Gavin hadn’t decided by that time, Max would no longer be obligated to return the favor. Most folks come up with a return favor fairly quickly.
As we've seen, killing a Fey before returning a favor is possible.
Since the Fey is no longer around to accept the favor, the magical obligation becomes null and void. Unfortunately, killing a Fey can lead to other problems.
The loss of one of the Court-bound Fey leaves the Courts out of balance. This is especially troublesome for the two most powerful Courts of Fey, Summer and Winter. The Courts must regain their balance as swiftly as possible, either by the Court who lost its member absorbing a new Fey into its ranks... or by the Court who's in the lead loosing a member.
Even the death of a lesser Fey may have consequences for the killer. Fey tend to hold grudges and have a fondness for blood oaths.
Unlike mortals, fey are creatures of pure magic. With their death all that magic is released.
The magical blow-back from killing a Fey can cause a great deal of harm to a mortal, especially if the mortal is not used to being around magic.
When offering a favor it’s best to be as exact as possible. Any loophole can, and often will, be exploited. RCSI has found accounts from the past of mortals asking a Fey to stop a loved one from being sick, only to return home to find their love one is now dead. In the Fey’s mind if someone is dead they’re no longer sick. Favor completed. While not what the mortal wanted, they’re still obligated to do a favor in return.
In the end, if at all possible, it is best to avoid Fey favors.
