Quote Originally Posted by ShunNakamura View Post
But the one character that I really feel needs fleshed out just can't seem to fit. It doesn't help that he isn't exactly a living thing to start with. And it gets worse from there.
You made me curious. Is this character by any chance an undead of some sort? If so, we've had our share of "undead" characters in the RP even if there were only a few of such. For example, a couple of important people in the plot have came back as sort of revenants (from both the good and bad guy camps, although such beings are in general rare), and we also have a lich as an important NPC.

I'll continue to play with him, but I am not really hopeful of coming up with a way I can fit him in without some major changes. At which point he is a different character and that kinda defeats my point of using him in the first place.
One of the ways I approached this dilemma with one of my characters was to adapt him into the story even if it meant sacrificing parts of his "essence" in the process. I've been RPing the character and it's been useful to see how he interacts with people, which gives me a better view of his psyche and worldview. Sometimes the plot even gives me ideas that I wouldn't have thought of otherwise, so it's all beneficial for the character in the end, and I can adapt those ideas into my story as well.

To make the long story short, you could try adapting your character into the RP and see how it changes him and whether it gives you any ideas that you could use for him in your own story. That has worked for me, at least, so maybe the same could be of use to you too.