So, backtracking from the Ultimate Cookie=Dozer since at the time I didn't realize Witch's Castles was in the Kingdom universe, I do want to connect other old cookies I've been hearing about (I read their wiki, don't feel oike watching a 1 hr post of pre ovenbreak rn, will do later probably, so sorry if I get anything wrong)
From my understanding, Kingdom/WC and Ovenbreak are separate universes due to events/devs, and anything post modern Ovenbreak story don't seem to be too much canon in their universe, so like GingerBrave apparently going into a witch's stomach or even having a brother. So characters back then aren't canon, but also free real-estate, as we see WC changes GingerDozer'a old lore into what we have now, but still kept some similarities like GingerBrave and him being brother-coded. What if they do that for UC if they aren't their own og character like I've mostly spoken about?
From the ones I read about (not that many), there are a fee that can come back into the story, definitely since the possibility of it being GingerBrave focused, or even just bring back into WC/Kingdom without UC's major involvement. G.B. BooDoo, while probably not UC given from what I've read about them, can be something/one used in the story to hurt GingerBrave, being a voodoo of him afterall. We also got ones who I believe would be good UC fits, Yolky Dokie who was apparently GingerBrave's lover (adding fuel to the Beast×Ancient/j. also I think is a boy? Idk, says he/him but I seen people draw hom as a girl? Beside the point), someone who was closed to GingerBrave and could even bring a redemption arc too if UC has one, and also Blazto, someone who is literally called the evil gingerbread and was sent by the witch, who can be switched to Dark Enchantress, to get/defeat GingerBrave and is most likely out of the two
But anyway, just a small UC theory as I do like talking about the possibilities with them, and even if it's not the UC case it would be fun to see them in the story of Kingdom/WC even if its a little thing or if they're not GingerBrave's voodoo/loverboy/rival, and ones I will be touching up on later, probably when I also read some of the space Ovenbreak stories. I still personally like it if UC is their own character, plus still like my whole theory on their movements and what they can do, but I'm fine with whatever