6th level Evocation
Classes: Inquisitor, Magus, Sorcerer, Wizard
Components: V, S, F (a sliver from an executioner's blade)
Casting Time: Reaction
Range: 30 ft
Target: One creature with a discernable head
Duration: Instantaneous
Saving Throw: Con Partial
Spell Resistance: Yes
Description: You can cast this spell only as a reaction to a critical hit that would deal slashing damage against a target with a discernable head. The target takes an extra 4d6 points of damage, and the target must make a CON save. If it fails, the critical hit damage multiplier increases by 1. After all damage is applied, if the target is at 0 hit points, it is instantly decapitated and dies unless it can survive decapitation.