Paper Mario Newcomer: Dimentio
The master of dimensions and pleaser of crowds, Dimentio here is one of the Paper Mario series' most iconic villains. With a wide variety of magical tricks up his nonexistent sleeves, I could envision Dimentio as a floaty mix-up fighter.
Retro Stages
My first submission will be
Super Mario Bros. Special, named after the eponymous game.
It's kind of redundant with stages such as the Mushroom Kingdoms, but where else am I gonna be able to talk about this... err, masterpiece? The stage cycles through a few different layouts. However, Pokemon Stadium this is not; Rather than a smooth transition, the screen cuts to black for a few moments before loading up the next layout, referencing Special's infamous approach to scrolling.
Submission 2:
Excitebike
Not to be confused with the Mario Kart 8 track, this stage hails from the Satellaview classic
Excitebike: Bun Bun Mario Battle. The stage takes place on the race track itself, with Koopa and Toad bikers occasionally driving across, damaging fighters in their path.
Submission 3:
Mario's Cement Factory
I actually have a specific layout in mind this time; The bottom row of platforms is a hard platform, the top row consists of soft platforms, and the hazard areas at the top and bottom chutes mark blast zones. Naturally, the platforms in the middle move in the same manner as the original game.
As for a stage gimmick, cement will occasionally spill from the canisters on the sides of the screen, covering the adjacent platform in cement and reducing fighters' mobility. If you're unlucky enough to get hit with the cement directly, you'll be covered in the stuff, rending you immobile until you break free. Combine that with the fact that you'd likely be right next to a blast zone if this happened... Yeah, try not to get too close to the canisters.