Why would you go as high as iso 800 if you were using a flash - maybe the exif is wrong - but if not I would step iso down to 400. Most stock photo buyers will not accept above 200.
It is interesting and the flash is under control without causing big shadows behind.
You have framed though his knees and that is not generally recommended.
To improve I would crop press off right since it is framed through.
To improve by reshooting I would try to get a between joint framing of the man.
it was at high iso for a previous shot without flash but at review I wanted some more light but not to overpower the feeling and wanted flame to still stand out..I couldnt move back much there was a chain in front of doorway and didnt want it in.
btw it was the built in flash which I feel gets a bad rap...decreased flash exposure by 1
