So it's been awhile since we've had this discussion so I'm just gonna reboot it a bit, with a slight addition.
Alright first off the evidence, from a variety of WOJ sources.
https://www.youtube.com/watch?v=OZJiv_GT-Jc&t=2409s starts at 15:00 minutes in.
"He's already Kringle when Kringles around...When he's acting in his role of Kringle he takes on the Kringle Aspect when he's doing that he's got all the power of a major lord of Faerie but he's also beholden to Mab while it's going on, Mab's no dummy though so she knows not to order him around. But they do talk and have strategy sessions and stuff like that. The Kringle is what Odin does to keep from dying of old age."
...Santa Clause, the Winter king who is not the commercial Santa Clause...anta Clause, one of the winter kings, is kinder, the spirit of generosity in a time of bleakness
Jim: He is wyldfae. He isn't a subject of Mab or Titania. That's what Wyldfae means. But his origins are in the Summer-side of the cycle of seasons, just like Titania's are.
Ditto Santa, only in Winter. 
(He /is/ beholden to Mother Summer, but basically everyone in Faerie is, so.)
(I mean, that's like saying "you must obey the law of gravity." Duh.)
He /could/. But that isn't the Allfather's style. Odin saw you coming last year, and he made his countermoves to what you're doing right now a week and a half ago. For guys like him, fights are what happen when you /fail/ to win with /real/ power--knowledge and forethought.
It's more accurate to say that he is /a/ Winter King. Or even more accurately, that he is a free Wyld Fae who is of a power level that is on par with Mab's and happens to neighbor her sphere of influence, and finds it simpler to show up to family dinners during the holidays and make polite than to start staking out boundaries and establishing treaties.
Is Kringle Fae?
His mantle, yes, is part of the Winter Court. Which does not necessarily mean that he himself is Fae as much as the fact that his mantle is. While he’s there, he’s got to pay deference to Mab. If Mab gives him a command, he has to obey it.
2015 AMA
Vadderung is Santa Claus, is he also St Nicholas?
And Father Christmas and Sinterklaas and a variety of others. But in our modern era, a lot of people wear multiple hats on the job.
If you’re (a powerful immortal being) in the real world, well, the problem is that you’re in the world, and you’re kind of mortal, and something could come along and try and whack you, if they’re fast enough, or good enough, or lucky enough. Which makes Odin a kind of special guy, because he doesn’t mind it, he thinks it’s awesome.
Okay so first the two Bold bits. These Confirm that Vadderung is Mortal or atleast partially Mortal enough to have to worry about aging and getting whacked. It also gives us a solid reason as to why Vadderung became or took up a Faerie Mantle to help combat his aging.
Combine this with Vadderung's Eye and the two theories that.
a) Vadderung took over the Odin Mantle at some point, due to taking up the title Vadder-ung. i.e. Younger Father
b) That Vadderung used to be the Gatekeeper.
My theory is this. That Vadderung was once a Powerful Wizard who through taking up atleast two mantles that of Odin, and Kringle expanded both his power and his lifespan.
The limits/exchange of this being that he has to pay service to Mab, with whom he has a working relationship and knows her well enough to comment on and give Dresden advice about her.
Never let her make you cringe--but never challenge her pride wizard. I don't know exactly what passed between you two, but I suspect that if it had been witnessed by another, she would break you to pieces. I've seen it before. Terrible pride in that creature. She'll never bend
We get a direct example of how the relationship and service to Mab works in Skin Game.
"The Winter Knight called for me in his official capacity as an agent of the Winter Court. Mab has the right to summon Kringle. If she'd called for Vadderung, I'd have told her to get in line
Legally speaking Kringle and Vadderung are two entirely different people who simply happen to reside in the same body
"Little games of protocol are how one shows respect, especially to those with whom one does not get along with famously well. It can be tedious but is generally less trouble than a duel would be.
So Vadderung is a significant enough entity in his own right to tell Mab to buzz off, but they have created a way for them to work together on cordial terms.
Legally Vadderung and Kringle are to seperate entities, personalities, identities and mantles, with different responsibilities, status and roles.
Finally in addition to the knowledge that Vadderung can tell of Queen Mab ruler of the Winter Court, we get the slight tidbit, that Vadderung/Kringle does not or has not always gotten along with Mab. To the point that theirs potential for a duel between them if they did have these little games of protocol.
My theory is that Vadderung puts up with these games of protocol and of the Kringle Mantle so that he doesn't age despite his apparent mortality.
So thoughts?
