>>44371864Already has been done. Shouldn't be done again unless it's part of some story element or apart of a few specie(s) evolution method.
I've played a Poke'fusion fangame before, and it was "interesting" as some fusions were cool, but a vast majority weren't. The fangame in question simplified it by having one fusion be the head, and the other be the body. This would never pass for any mainline game nor even spinoff. GF would need unique art designs to properly merchandise EVERY fusion, not happening.