They could easily make her an archfey.
But that doesn't solve what I think they were going for, which was the Shadowfell-equivalent to an Archfey. As it stands, there are quite a number of characters from folklore and the various editions of the game that are considered under the designation of Archfey. If you go to
THIS THREAD on the Candlekeep forums you can find a huge list of characters, mainly from the 4E books dealing with the Feywild, that could all be consider potential Archfey patrons.
But what is the equivalent list of Shadowlords? There really isn't any. The two biggest names that were designated as living in the Shadowfell were the Raven Queen and Orcus-- one of which is a god (and thus not a patron) and the other is a demon lord (and thus would fall under the Fiend patron designation.) The only other entity that I know of and can remember that lived in the Shadowfell as a potential Shadowlord patron (and I know this because I have a player whose Warlock PC was specifically created with Shadowfell patronage) was the archlich Mourne, from the
Shades of Darkness organization article in Dragon 387. And even he's technically undead and thus should really be an Undying patron.
I imagine there are probably other entities named in some of the various 4E Shadowfell-based articles or books, but none of them have gained any real foothold into our consciousness. Especially considering that unfortunately, most of the powerful entities you might consider for Shadowfell patronage are actually undead too, and thus would also fall under the Undying patron as well.
Which is really why I have to wonder if Mike & Co. were actually thinking that quite possibly the most well-known "evil" and "darkness" type of entity that was NOT already a god, devil, or demon was in fact
Blackrazor. Which is how they came upon the idea of using Blackrazor (and other evil intelligent weapons like it) as the potential patron for Shadowfellian PCs. Personally... I'd love it if they just went through their history to find other "Shadowlords"-- shadow or darkness-based entities that are not gods, demons, devils or undead that they could begin to emphasize and build up to the level we already have for all the various archfey. But my guess is that's a tall order and easier said than done.
