Hi Marietto,
I’m not sure if you will be able to get help on Ebsynth here. You could try the ebsynth forum if they have one or blender artists. Perhaps someone over there knows about it.
I don’t really know anything about it but from your image sequences it looks like you are not feeding it enough keyframes so it doesn’t know how to interpolate. The Ebsynth demos look like it is taking every frame of a video as input, not just what you have decided is a keypose. But as I said, I have never used it and I don’t know anything about Ebsynth.
Sorry I can’t help 🙁
