In the September 2014 balance patch, the leap part of Fiery Greatsword 4 was supposed to receive a +140% damage buff as the fire trail was nerfed. Only the tooltip received the buff and the actual damage dealt by the skill is unchanged. This would make FGS used as an Elite for more than just mobility.
This balance change was supposed to be implemented several months ago and I hope it can implemented soon.
Thank you