There's not technically a rule that specifies you can't do that, but if we start doing that I can bring back my Weapon:Ashen character and give him a several month run fueled entirely by my old material as him. I think I have 70+ RPs saved somewhere.

Here's the best way to think about things of this nature... if you are wondering if it's ok for you to do something, just multiply it and pretend everybody was doing it. What picture do you see in your mind if that happens? Is it a good one?

My best advice is to use old material sparingly. It's only going to hurt you if all of your material is all pre-written because that means it will be absent of any XWF relevance, which is a negative in most judges' minds. There's nothing wrong with maybe recycling some pieces on occasion, but judges are going to be able to sense if you pasted a bunch of old material or if you actually are RPing for the match you're booked in... and if they sense that, it will hurt your performance that week.