But Rayman NEEDS his grimace from Rayman 3 as a taunt, the one that reverts hoodlums to red lums. Also I hardly imagine a character making a cameo for a taunt, if anything I imagine Globox appearing in his victory pose similarly to Chrom/Robin. A Globox Assist Trophy could be cool as well - for example, he would move and jump similarly to Magnus or Ghirahim if there's no enemy close to him, and attack with the tiny storm cloud he uses in Rayman 2 to open laser doors. Though this would require the ability to add DLC Assist Trophies, and I admit it would be criminal in a way to have a Rayman Assist Trophy over a Donkey Kong or Pikmin one
I think that the Japanese blue Rayman needs to be somewhere, because his shirt has its color changed to blue in Japan for cultural reasons - purple being the color assiciated to death. And it would even probably be his default color in Japan, with the purple one being default everywhere else, similarly to R.O.B.
As someone who wants Rayman for primarily nostalgic reasons I hope that he will come with elements not coming from only Origins and Legends. I have not played those games yet, there's probably moveset potential coming from those games, but I don't want to be spoiled about moveset potential or other contents from at least Legends. But oh God I would be so hyped if he could summon a purple lum with a light rod for his recovery, ride a shell*, or use various power-ups from Rayman 3.
* I'm French and I don't know their English name, I just gave a litteral translation of their French name "obus". I'm talking about those running yellow explosive things you can ride from Rayman 2. Oh, being French is yet another reason for me to want Rayman, due to him being a French mascot!
Rayman 3 is my second all-time favourite 3D platformer, just behind Mario 64, and I'd love to see a new high-quality Rayman 3D platformer with its charming universe and humor. Take what made Rayman 3 good, add even more secret zones and make it a bit less linear, and it would become a day-one buy from me as well as an actual competition to Mario, the only franchise with high-quality 3D platformers nowadays. I remember those days when I was a kid, I thought that 3D platformer were the most common video games around, and I associated video games in general with this specific genre. Oh God those times are now far behind me.