[quote=@Professor_Wyvern]
For a crossover really you couldn't ask for anyone BETTER than Santa, because he's done this game before. As compared to the various characters who are really more applicable to their own story. Santa Claus is applicable to any story. Santa could be in any real genre and place. Other characters only really fit in their timeline, while Santa is timeless and universal.

He would be far more used to the stranger aspects of dimensional traveling. Such as Doctor Who Santa. He's pretty used to the weird man who travels through time and space and has helped him out in a few of his shenanigans and has been helped by the time traveler. 
[/quote]

The GM has said no. That's the end of the matter.