I see the Krampus as being an element of the Yule Court. Just as Jenny Greenteeth (a water hag) was a part of sex kitten Maeve's court, Krampus and the other companions are extensions of the power of the Yule Court.
In theory Maeve could use the hag powers of the winter court, but she preferred to have a servant do it. Similarly Santa could punish as well as reward, but he prefers to have his servants do the unpleasant things. The legend of Knecht Ruprecht says that he "represented an archetypal manservant" - and in those days the servant would handle the unpleasant tasks that the lord didn't want to deal with.
I guess it comes down to the role you envision someone with Yule Magic filling. Is he a servant or companion of Santa Claus, or is he an extension of Santa Claus? If the first, then it makes sense that the servant would fulfill some of the roles of the other servants that Santa Claus have done.
But there's another way of looking at things. In the DV, the myths usually come out more historic than Disney. Toot-toot and Tinkerbell might have sprung from the same legends and there are times that Toot-toot and his fellows are nearly Disney cute. That time in Summer Knight, where the little folk are forming up in a military unit - I can see Tinkerbell being in a scene like that. The thing is, I can't Tinkerbell using a box cutter to rip the Summer Lady apart. I really can't see her killing anyone - Summer Lady, Captain Hook, anyone.
Tinkerbell is the Disney version of the little people. The modern Santa Claus - who always brings good gifts and never gives lumps of coal - is a Disney version of the Santa Claus. I see the DV version (described as "he's not what you think") being closer to the old myths than the Coco cola ad.
Richard