Try not to make the sprite so big. It's easier to animate on a smaller scale. Never upsize your sprites  as well, just post them as they are, the website has a zoom tool by just clicking on the image. Work on your shading gradients, try to add a glow effect instead of transparent embers. To me fireballs should be flowing, glowing, or moving in some way. Yours just looks kind of like a floating ball of half melted cheese. Maybe add some more frames for a more fluid cloth flow. The fire embers in yours look kind of strange. I'm surprised the cloak isn't catching on fire.
Here's a quick take of mine on it.

Try using photobucket or imgur as an image host. But really you should try working in a smaller scale. A big mistake of most beginners is they make their sprites too big.