Weapon Evoker Mastery (Item Mastery)Source Magic Tactics Toolbox pg. 31
You rack opponents with eldritch power coursing from your magic weapons.
Prerequisites: Use Magic Device 2 ranks, base Fortitude saving throw bonus +3.
Benefit: As a swift action while wielding a magic weapon with a weapon special ability that deals extra acid, cold, fire, electricity, or sonic damage on a hit, you deal an additional 1d4 points of damage of the same type with each hit you make with that weapon for 1 round.