I have an existing flash SWF and the source FLA.
It is close to being right but needs to look more like an explosion of light. Not like fire, but more like a bright flash of light that comes out of the center slowly and then suddenly gets so bright that it turns the entire screen almost white. You need to be really good at changing an existing flash. This needs to be done quickly and it needs to look really good.
Please post samples of any flash you have done similar to this and if your work looks good I'll send a preview link to my current flash for your review.