Oh, might as well share something. It should be viewed in the context of A) Me trying to create a cool custom merit for a high-level character that I thought would work, at least somewhat well, but might need work and B) In the game/Quest I'm using this in, I've unharnassed Seeming from Kith, so you can now be an Elemental Chimera, Fairest Hunterheart, etc, etc right out of the gate, basically using the best parts of 2e that I like.
[?]Neither Fish Nor Fowl
Prerequisites: Wyrd 3, Chimera Kith
Effect: Seeming is an abstraction, and one that you can step beyond, or rather change. Just as a chimera is a beast of many parts, the Changeling with this Merit is a being of many parts. A number of times per day equal to half their Wyrd, rounded down, by concentrating for fifteen minutes--they may go about normal routines, but can't be fighting, doing heavy-duty magic, or anything that would seriously distract them: eating breakfast is okay, writing a symphony isn't--they can change their Seeming. This comes with all relevant Blessings and Curses, but does not provide any advantage towards the purchase of affinity Contracts, being implicitly temporary. The Changeling's appearance changes along with the Seeming, in relatively subtle but definitely noticeable ways.
A/N: Not sure on the restrictions or so on, I just didn't want it to be an automatic thing, but I ALSO didn't want it to be some sort of weird magical ritual, so I was imagining it more as concentrating on changing...and then you do. I'm also quite okay making it so that your Seeming snaps back at the end of the day, or the like. Wasn't sure about that part either.