I know it's a chance i've used the weapons alot. But since it gives Fire Dmg but still hurts Ifrit you'd think FoF would do damage to Ifrit. FoE atleast still raises dmg done to ifrit. And, it's not like FoF actually healed ifrit much it usually nerfed the dmg then the extra that went through healed. Since like a Blindsided/Blood for Blood Howling Fist for me usually does ~800 dmg on Ifrit but a FoF buffed Howling Fist only healed him for ~50. It was really quick to figure out FoF was healing him though since on a 2nd Battle chat Log only dmg that was showing on it was from the additional fire dmg procs of Ifrit's Claws.