While not exactly similar to clones, I'd love some more costumes in Smash 5. Costumes like Alph, M/F Robin and Corrin/WFT, Villagers, and definitely Koopalings are what I want to see when it comes to similar character representation. Characters that deserve to be in Smash, but not enough to get a new moveset or even be a clone. If implemented well, model swaps for existing characters can be one of the best new forms of representations in Smash. Masked Luigi, Masked De De De, generic FE swords being Marth costumes, and many others can be nice compromises between being clones and existing characters.