Press-Gang the Soul
Phase cutlass strikes store enemy souls that fuel Wisp Ally castings at will, heightened to half your level. When wielding a phase cutlass with stolen vitality, you can release one...
Your phase cutlass steals some of the enemy's vitality, press-ganging it into eternal servitude. As long as you are wielding a phase cutlass with stolen vitality, you can cast Wisp Ally as a divine innate spell at will, heightened to a spell rank equal to half your level. Using Wisp Ally this way requires and permanently releases one soul press-ganged with your phase cutlass. The first time each round you Strike with your phase cutlass, you immediately gain the effects of the Sustain a Spell action, which you can use only to extend the duration of and control a Wisp Ally spell cast using that phase cutlass.