Kamui seems to be a bit more acrobatic and speedy of a character to me (IDK why though), so I think that if they were to use their terrain manipulation as a recovery, they would create a platform and immediately kick off of it instead of the platform having some sort of permanence (resulting in something more like Lucario's Extreme Speed instead of Pacman's Trampoline).
I'm now torn on whether I want that or Let's Turn into A Dragon and Fly as a recovery.
I think that I'd rather have the terrain manipulation be their smash attacks, so Kamui would be even more distinct from the rest of the FE reps.
My ideal Kamui would have them using their sword as little as possible, and since they've got terrain manipulation and being a dragon I think that they'd easily be able to limit sword attacks to tilts and the jab.
EDIT: forgot to ask the question this was leading up to
That in mind, would you want Kamui's moves distributed like Robin's, with Specials, Tilts, and Smashes each representing a particular aspect of the fighter (sword, terrain, and dragon in Kamui's case), or would you want it spread and mixed across their Specials, Tilts, and Smashes?
I think that I would want them mixed, both to further distinguish them from the rest of the FE reps and to take full advantage of the sheer versatility of Kamui's abilities.