Flametongue

This masterwork Flaming Burst (deals +1d6 fire damage on hit, +1d10 additional fire damage on a critical hit) Longsword can be activated once per day to blast forth a fiery ray at any target within 30 feet as a ranged touch attack, dealing 4d6 fire damage on hit. The fiery ray is subject to spell resistance, with a caster level equal to the wielder's HD/level.