Something about his potential play style (detached limbs and all) seems somewhat interesting to me. It sounds like it could be quite fun in a game like Smash.
Perhaps if I could be convinced of his qualifications as a Smash candidate, I might support the idea. I'll admit, my knowledge of Rayman is quite minuscule, so I'm not exactly sure who he is or where he stands in the history of gaming and Nintendo.
Well, I've already been going about with Blue Pikmin for it, but I'd be glad to give you a run down!
Rayman was "born" in 1995, first appearing on the Atari Jaguar. Though his first game wasn't on Nintendo consoles, and was most famous as a Playstation game, he still started out with a very interesting history with Nintendo. His first game started production for the SNES, it had two player co-op and everything, though that (and other things) was scrapped when production shifted.
His second game did come to Nintendo, however. Rayman 2: The Great Escape, often heralded as one of the greatest games of the time, and even the best of the franchise, brought a lot of things to the table and really put Rayman on the map. The sheer number of times that this game has been ported is ridiculous, it's been on everything from the DS to a phone. A lot of Rayman's potential for specials come from this game, including the classic energy sphere that was his main form of attack in the game.
Rayman 3 changed the formula a bit, but it did bring some cool stuff, like the Laser Washing Powders. These powerups changed Rayman's outfit and gave him unique abilities for a short time. The best way I can see these implemented are as Rayman's custom specials, as detailed in my moveset. After this came the Rabbids games... we don't talk about those.
Rayman Origins and Legends went back to the classic 2D format, but definitely came out more fluidly and speed oriented than the first game, which relied more on combat and platforming. They also gave Rayman the perfect attacks to use as standard moves for Smash. Like seriously, he's got the tilts, the dash, the smashes, the nair, bair, fair, dair, uair, etc.
He was also made Ubisofts mascot some time in the early 2000's, so he certainly has importance to them and the industry.
In regards to Smash, there are so many ways he can be made unique. He has a projectile attack, but he also has physical attacks with the range of projectiles, he would probably even have the furthest grab range. His helicopter hair gives him a unique option, while normally he would fall very fast (around Fox speed), at the press of the jump button, he could slow his fall to Jigglypuff's floatiness, the mind games and tactics to be made of this are numerous. Naturally, he'd be amazing in the air, but he's also a competent grounded fighter, though keeping opponents off of the ground is definitely in his interests.
We'll definitely be glad to have you on board as well!