Couple times I've written characters that made me go all like "something doesn't feel right," and it turns out I'm just not really enjoying writing them.
Stuff like this doesn't just happen to side-characters - main protagonists and antagonists are at risk of this, too.
And I heard, I forgot where tho, that if a character you're writing seems bland and unenjoyable to you, chances are the majority of the audience are probably going to feel the same way.
