Rayman is another character that seems to have been overlooked by Nintendo in the past for Smash Bros. inclusion even though he clearly deserves it at this point. He was requested in Smash 4, but his popularity was waning at that point, only to be revived by one of the most critically-acclaimed platforms in recent years in Rayman Legends. It would be unfair to include anyone from his franchise before him, and as that is now increasingly likely with the advent of Mario + Rabbids: Kingdom Battle, Rayman needs to be added to this iteration of the game.
Rayman has a littany of games to get his moveset from and would likely get a lot of mileage out of his detached limbs. He could be one of the few characters to have a ranged grab that is made only out of his body, which would bring a unique and fresh character to the Smash universe.