Mulan & co. get bored of being ancestors, so they recorporealize in the modern day. (which, of course, takes away all of the fun issues of Mulan)

Would preferably involve a lot of annoying the descendants, both on purpose and on accident.

(Hmm, I guess I could do the last part in the Dinosaur verse...suddenly, Mulan shows up at the house of the descendants of one of her adopted kids/one of her friends' descendants. And proceeds to annoy the shit out of them, who are used to thinking of her as an honored ancestor/honorary ancestor.)