Super Smash Bros Ultimate has the largest roster in series history, having a massive roster, even before the dlc was announced. There are many characters fans have wanted for a long time but many have been relegated to the role of serving as mii outfits. These outfits give the ability to customize the mii characters and dress them up as various characters, but the truth is that the game could go much further than just mii fighter outfits when it comes to the idea of dlc skins.
To explain what I mean, let us take a look at Street Fighter V. Capcom’s latest Street Fighter game has a large amount of DLC costumes for the various fighters to wear, many of which reference other Capcom games. Some of these games referenced include Darkstalkers and Mega Man for instance and this is something the developers should look into doing for Smash. This can be incorporated into smash in a few ways, such as costumes the characters could wear. For instance, Samus could have a new power armor skin that makes her resemble other characters including perhaps a certain highly requested Microsoft character, while a character like Greninja could have a Strider outfit, considering how many fans feel there is a similarity between how Greninja plays and how Strider plays in the VS series.
Another possibility is to have alternate skins that would allow you to effectively have additional characters in a manner similar to echo fighters. For example, Terry could be given skins from other SNK fighting games, while Ryu and Ken could have additional skins for characters like Akuma and Dan. Link could in turn have a skin based on characters like Adol Christin or the often requested Takamaru, while Villager could actually become Balloon Fighter.
If the base character is a good fit, this could be a way to bring in many fan requested characters who would otherwise take more development time. Perhaps indie characters such as Shantae could make debuts as well, going over an existing character and give the fans something to enjoy. In addition this could be a great way to judge fan interest in characters by seeing how well these outfits sell and could even help to determine if the actual character might do well in a future Smash game.
Obviously this is something that requires a lot of thought before implementing, since just slapping a skin on a character is not an easy thing to do. The second idea would require a lot of attention to ensure no glitches and that the gameplay makes sense, but the first method would also be a great way to reference requested characters. But additional characters are not the only reason for dlc skins, as we could have characters with outfits and skins based on other games in their own series. Luigi could have a Mr. L skin, Shulk could have his look from Future Connected, Ryu and Ken could have their Evil Ryu and Violent Ken designs respectively and Mario could have the iconic Fireflower Mario outfit. In addition, we could see Bowser have a Dry Bowser skin, a Garou era look for Terry, new outfits for King K Rool and more. Perhaps Peach could have a new look that resembles Pauline, or Mega Man could have new looks that allow him to look like the other Mega Man incarnations instead of relegating these to the Mii Fighters.
This would also be a great way to sell more DLC and gauge fan interest, and though this would require a lot of work still, it is something that Sakurai and Bandai Namco should consider doing in the future.