Having played through the game, I definitely agree with the support here, to the point that I made an account just to support it. It's a very innovative IP, full of unique charm, excellent soundtrack, and since it seems to be selling quite well, that would be a very smart decision for Nintendo to push their new titles even more. So spoilers ahead, I'll be talking about the movesets I can see in the character.
In term of moveset, I'm torn. I could see two main design directions, one of which is the already heavily mentioned Ice Climbers/Luma type with a semi controllable Legion.
But I'm personally not a big fan of the gimmicks introduced by more recent fighters. Fighters can be innovative without having entirely new mechanics. So I could very well see a more orthodox moveset based on the X-Baton for move variety of the physical attacks (side smash is the glaive, up smash is the gun, normal combos are the baton, etc), and apparitions of the legions in things like special attacks and smash attacks. The Axe Legion gives a nice down-B with his counter/shield, I could see an arrow as a neutral-B, and side-B could be a chain wrap/stun, or a legion dash. Or you could see the legions appear during smash attacks much like how Bayoneta has those summoned limbs smash for her, so with a side-smash being the Sword legion dashing out, up-smash with the Arrow or Beast legions doing something, down-smash with the Arm legion spinning, etc... And the final smash to me is obvious, it's also the most epic move you can use in the game, even if it is a spoiler in some way. Anyways, that would maintain the aesthetics and personality of the character while making it very Smash compatible.
Also, I could see Echo fighter potential... I don't know how they plan to deal with Echo fighters from now on, if it's limited to those few or if future fighters could be released in duos, but let's say team Raven would make for a good candidate (although I guess it'd probably be a skin).