Searing Foehn (3.5e Maneuver)

Your flaming sword turned bright blue and raged with a heat unnatural, channeling all your spiritual force through every attack.

When you enter this stance, any fire damage you deal is more potent. While in this stance, your fire attacks are so hot that they ignore the fire resistance of creatures affected, and creatures with immunity to fire damage instead take one-half the normal damage dealt.

This applies to both maneuvers and magical items, such as a +1 flaming longsword. It can be used on magical attacks, but only up to 3rd-level spells. This maneuver is extraordinary, though the attacks which use fire damage are often supernatural.