A flashgun is an essential bit of kit for the serious photographer. Unfortunately, when mounted on a Fire Compatible Speedlight and pointed directly at someone's face it can give some unpleasant results. You've probably seen them yourself, flat lighting, harsh shadows, shiny skin and red eyes to name a few.
There are two possible solutions to this. One is to bounce your flash off a ceiling or nearby wall. The second, who gives more control, is to get the flashgun off the camera completely.