So, I have like, opposite your problem. :’) I find it harder to write original characters usually. XD
But anyway, while I’m obviously no expert, here are a few tips on how I write em!
First off, when I think of writing Jon or any of the rogues, I try to envision a few key points of things they would/wouldn’t do, and keep them in mind. It’s easier for already established characters because their personalities are already set with specific guidelines from which character development can grow without making them too OOC. You take what you know from canon and work from there. For me, this causes a sort of character profile stemming from the facts I know about them and my perception of it. It helps to recall the symbolism you may have learned in literature classes.
[These are only my personal opinions on his character, a bit behind my version of him. So don’t take it as set in stone accuracy…:’) I’m sure lots of people wouldn’t agree with the analysis I’m about to give, so…///)]
Take Jonathan Crane, for instance. We know his background, his profession and how he works with others. As an abused child, a social outcast and someone who was rejected by someone he had feelings for, he has become an incredibly private, anti-social individual.
His study in psychology suggests he has an interest in how the minds and reactions of people work, therefore rather than forsake people altogether (as one might initially assume) he perhaps wants to see why people are the way they are, and in a way to understand them as well as himself.
His profession in psychology as well as a former therapist working at Arkham suggests he wants to be in control while inadvertently helping others. Now, of course, he has twisted his interests into finding the fear of others and causing them to feel it, which obviously suggests he himself has deep psychological issues (which he probably wouldn’t deny but also would not seek to dwell on either). Causing others to feel fear and having such an unseemly obsession with it suggests he is comfortable (relatively speaking) with the concept of fear (not fear itself incidentally), meaning he has experienced it firsthand often in his past (which we now know to be true).
His study of the human mind would also further fuel his cynicism and overall pessimism (though I find him to be more of a realist under normal circumstances) as psychology tends to focus on natural human nature rather than the higher potential humanity can achieve.
His unrequited feelings that lead to such disaster also influence him in the fact he does not seek out companionship of any sort. He also does not work well with others, tending to double-cross them, meaning he does not trust easily—if at all. He has little to no experience in friendship and was content to focus entirely on his goals of tearing down or ruling Gotham through the fear he himself is far too acquainted with.
From this I have worked out a character that develops into something far more interesting (to me anyway) than what I’ve seen. People tend to focus on his bloodlust, his high off of fear and his lack of emotion, which has become incredibly cliché.
In my current character development I portray Jon as quiet and somewhat humble, more sure of himself. (I find Riddler to be the one who should be the egotistical one but I digress). Since he has no interest in the opinions of others (until he actually implements a successful scheme) he would have no purpose in gloating. He also finds small-talk to be boring and insufferably cumbersome when conversation can be used to get into more interesting topics; that is, if ever got into a conversation. He has never sought out friendship, and only engages in socialization when his psychological interests are piqued (as seen when he first met Jervis Tetch). Once he loses interest in a person, he moves on, like the detached scientist he has become.
And this is where things change. He is a part of the Rogue Gallery, full of rather unpredictable people with whom he seems to fit in with. And in finding a group with which to fit in with as well as a common goal (defeating Batman) has indeed softened his nature if only by a bit, for this alone is a sort of inclusion/comradery he has lacked almost his entire life. His first true friendship has been with that of Jervis Tetch, who has since made it clear he places full trust in Jonathan. Jon, not having ever had someone trust him like that before in his entire life has yet to betray it (knowingly or consciously). Because in the end, trust is something he himself has never truly had in anyone but himself—but now someone else trusts him too. This is what makes him value Tetch, and to some lesser (and I mean lesser) extent, other key Rogue members.
Jon’s destructive nature is exhibited in spurts, for as an intelligent individual with such a troubled background, he would tend to keep things bottled up until things found their own outlet (I base this observation by my experience with other abused people I’ve known in real life). That is why he finds the need to do crime and practice his experiments of fear, it is not quite an addiction (most of the time) but not something he is able to choose not to do by sheer will alone (yet). It is his passion yet his curse, for it reminds him of his past in order to understand his present and perhaps future. And it is something he can’t totally control, something he has seemingly struggled with throughout his life.
I hope that helps? I dunno, this is just my Ronnie!Canon I suppose. But here ya go luv, a long-winded character analysis and some wonky doodles.:’) I hope this does help though. Let me know! And good luck with your fanfic!