Here's the problem we're dealing with, in the case of Fat Princess.
She's, obviously, not one of the all-time greats. She is first party but, very 'weird'. HOWEVER. She has a unique moveset. She's something totally new to the game that nobody else can emulate.
This 'is' a fighting game, and for a fighting game to have a diverse roster, this is a pretty good idea. This is actually why I defend Evil Cole as well; while he's, yes, Cole, if you look at his moveset not many other characters shoot entire beams for their Level 3, epecially while flying. He looks a lot like a heavy hitter, especially compared to his weaker counterpart who more than most likely has to rely on crowd control and zoning.
With Fat Princess they had the freedom to do pretty much anything with the moveset. For anyone that has actually played the PSN Fat Princess, she's a game of Capture the Flag. I mean, literally, 'she' is the flag. I called it Capture the Flab. Because of this they were able to create a unique moveset that nobody else in the game could probably pull off, and that's what makes it fun. Ballerina spins while falling down in a shockwave attack. She looks to also be a heavy hitter; kind of like a Zangief, or Big Daddy, because she can throw her weight around.