Hah took me a bit to think about but-
In comparison to the rest of the Disgaea 4 cast, Fuka reaches the point of annoyance with me more than anyone else since she's a pretty convincing teenager character. Sometimes she annoys characters or becomes very one track minded and it bothered me a bit more than the other's character quirks.
And while this doesn't have to do with Fuka's character, the ending for the Fuka and Desco show made me felt sad and pretty mad as it acted as a satisfying conclusion for her character then turned on its head when Flonne came out of nowhere to give her little to no chance at being reincarnated. I understand the decision to conclude her character while still having her stay, but I really wished they at least kept it ambiguous whether Fuka ends up reincarnating or not for potential story sake. (Might just be me rooting for sadder stories tho)
Tbf tho, this is a series full of evil characters with little to no comeuppance, Disgaea 4 is no different. But how they handled Fuka made it hard for me to see through her irritating moments to her more endearing moments. Which I did end up finding after re-watching the scenes again. Love her development with Desco, Des X, and Val also how she basically comforted Emizel after his father disowned him, also how she was technically Fenrich's comeuppance for being a manipulative jerk.
She's definitely not the worst character in my book (I honestly can't say who is) but she gave me a bad aftertaste for awhile since she's one of the loudest of the bunch and the Fuka and Desco ending irritated me. But after looking at it again I don't feel as negative about her as I might've felt when I originally wrote that sentiment. But I think that statement still holds true for me.