How to get characters like Mukai and Robin compatible with all characters?

[Jsnjnbsww]

How do you get characters like Mukai and Robin compatible with everyone. they only work using very specific characters

[1UPermario]

I think it has something to do with the sprite index or sprite number it looks for when calling the sprite for the victim but don't take my word for it. I don't code characters, and I haven't really tried going around changing sprite numbers in the cmd or cns files nor will I ever feel the need to attempt to. I might just be straight up wrong or maybe there's no way to at all...