loneprison Well, it is possible to edit the exported skeleton data and modify the animations, whether using Unity or not. However, I can't think of a quick way to mix animations in Unity and import it back into Spine. I can't say for sure since I don't know what documentation you've actually seen, but my guess is that the author is using some proprietary tool he's created himself. At the very least, I can tell you that such an approach is not a common one.
