Maybe if I keep saying it, it'll come true!
I am here to rant about characterization.
Characterization can be hard, we know that. Some characters are even harder to characterize than others. The KH fandom has its work cut out for it-- many of the characters people like to write for aren't fully fleshed out even in canon, but in fiction, they have to be. Especially in longer pieces. Not only do they have to be consistent, but they have to be believable.
Here's one of my, albeit many, pet peeves: authors that can't back up their own characterizations. The axiom of "show us, don't tell us" should be gospel, it really should.
Example: you're writing an Axel/Larxene PWP fic. There's some witty banter, Larxene makes a few token attempts at being the sadistic bitch we all know and love, but then Axel gets to work and-- well.
Don't write, in your narration, that Larxene is the top and in control of the situation. Have her actually be in control! First of all, failure to do so is just shoddy storytelling, second of all?
It doesn't matter how many times you tell the reader that Larxene is in control, they won't believe you. Especially if Larxene is just lying there, cursing and spitting but not doing anything about being taken advantage of; because clearly, a bit of clitoral stimulation renders one immobile. That's the only reason I can think of as to why your Larxene-- who is totally a dominant!!!! OMG and unhappy about the situation-- didn't jump up and tear Axel's face off.
I can almost buy this characterization of Larxene on its own. I wouldn't like it as much as others, but I can buy it. What will jar me, and any other reader paying attention, is the insistence throughout the narrative that she's in control, and not Axel's plaything in spite of what's actually going on in the story.
In short: learn to characterize!