I don't think you need the photoshop filters. If you're going to do that, go nuts with it. I like the disc thing, it gives the attack more pop. The projectile looks a little like a mudball though. It's fairly difficult to draw fire in anything other than its flame form and get it right. With practice I don't see that being a problem. You might want to work on your cloth folds some more, and maybe refine some of your linework. Other than that though I think you did a pretty solid job.