Mage Hunter Feat 6
Source Pathfinder Advanced Player's Guide
Prerequisites superstition instinct
Trigger A creature within your reach Cast a Spell.
You use your hatred of magic to lash out at the sight of spellcasting, allowing you to interrupt an enemy's spell. Make a melee Strike against the triggering creature. If the attack is a critical hit, you disrupt the spell.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
BarbarianThis indicates abilities from the barbarian class.
RageYou must be raging to use abilities with the rage trait, and they end automatically when you stop raging.