Mythic Severance

Necromancy [curse]
Level: Artificer * 4, Cleric */Oracle * 4, Inquisitor * 3, Sorcerer */Wizard * 4, Warlock * 4
Components: V, S
Casting Time: 1 Standard Action
Range: close (25 ft. + 5 ft./2 levels)
Target: one creature
Duration: permanent
Saving Throw: Will negates
Spell Resistance: yes
  You restrict the target's access to its mythic power. Each time the target attempts to cast a mythic spell, expend mythic power to activate a path ability, or use any other effect that requires expending uses of mythic power, it must attempt a Will saving throw against the DC of this spell. If it fails this saving throw, the creature loses its action and the ability it was attempting to use has no effect. This spell has no effect on mythic abilities that don't require the target to expend mythic power.