What's the point of Namine? She, more than anyone, feels like a plot device. Not that that's necessarily a bad thing. First I thought she was part of the Roxas-Axel group, making up their own trinity, but then Days replaced her with Xion, and now Axel isn't even a Nobody anymore. But for all intents and purposes, the games seem to frame Roxas-Lea-Xion as their own trinity.
Not that Namine has to be part of one, but when every single character on the cover of KHIII except her makes their own trinities, she feels out of place. The whole "nobody remembers Namine" thing makes it seem deliberate. I just feel kinda bad for her.