If I make no sense, let me rephrase...
The box underneath the walkability editing box, titled "next:" lets you choose another combo. I tried an animation, thinking it might be something that cycles through an animation, then stops (which would be awesome) but my combo still continued to cycle... I'd like to know what something that is assigned in this box would do.
what is "next" combo data in the combo editing screen?
That "next" combo is used for combo cycling, animating from one combo to the next.
Just like with custom bosses, check out idontknow's ZC tutorial on the Quest Editor Help page. Trust me, that tutorial answered most of my questions concerning the latest version of ZC.