So there's a character handler (aka roleplayer) who you feel writes either more than you, or just "better than you." Before you decide you don't want to write with them, consider the following:
Hands-on experience is referred to by many as the most beneficial and efficient way to learn.
While you may not always agree with that, just hear me out. I came to PA after a space of about two or three years in which I didn't consider sites like this. It wasn't for lack of using them before. No, I have been on a good few sites like this one over the years, and always Harry Potter related. But I had so much going on that my writing fell to the wayside.
I recently found my first in-character post on this site. It was shockingly short and the vocabulary was impressively bad. Going from that to my recent thread for Darren Isaacson and Erika Dixon, it's actually amazing (even to me) how much my writing has grown.
This wouldn't have happened if I hadn't told myself to write with those I feel were (and still are, undoubtedly) better writers than I am. Every day I look at my recent posts and chide myself for something I've done that I realize later wasn't the choice I wanted to make as a writer. I'm not saying that you should be hard on yourself. I am only this way because I want to hone my skills for a job down the road. Plus, I'm a little bit OCD. Or a lot.
So what AM I saying? I'm suggesting that you look back on old threads, see how far you've come. All of us have learned new things and grown from our time here.
Next, get in touch with someone whose writing impresses you, and ask to thread with them. If you feel open about it, say you're wanting to learn from them through experience. The members who you contact will undoubtedly be thankful that you've passed them high praise like that, and I bet they would love to help you out. It certainly won't hurt their writing, and it opens up new plotting opportunities.
Then, in your thread with this new person, watch for things that they do that you either do or do not like. You probably don't want to point out the negatives to that person -- we each have our own style, which makes it a lot more fun. But you do want to find things that you can learn from and decide which things you don't want to include in your posts or your writing.
You SHOULD: thank them for helping you, if you told them the reasoning,
But you SHOULD NOT: copy anything directly from their posts. Don't start taking their metaphors or opening sentences. This is for you to learn to build your own skills, and not to plagiarize anyone's work.
In the end, you should come out with the ability to write longer posts with perhaps more thoughts, or details, or better dialogue -- whatever it is that you want to work on. This is in no way a requirement or anything like that. This is, instead, a process through which you can better your writing and hopefully feel less of that Writer's Envy that we are all so prone to.
*Note: if you are wary of approaching a member you don't know, you can always ask a Mod or Admin. As Khaat posted, we're around to offer skills training for anything from writing regular posts to specific instructions in dueling, how to write as a werewolf or vampire, etc. Just shoot a PM if you need us.