Needs review
Source: Pathfinder: Ultimate Magic

Description: Your spells carry an embedded curse that manifests when they strike true.

Prerequisites: 9th Level Caster, Can Cast Bestow Curse

When you confirm a critical hit with a spell or spell-like ability, you may cast bestow curse or major curse on that target as an immediate action. This works even with ranged spells. You must have Bestow Curse prepared or otherwise available to cast, and using this ability casts the corresponding spell.