Spellvoid

Glow (aura, light) — 20 feet. A will-o'-wisp is itself naturally invisible, but glows with a colored light, casting bright light in the aura and making it visible.

Magic Immunity — A will-o'-wisp is immune to all spells except Faerie Fire, Revealing Light, Force Barrage, and Quandary.

Feed on Magic (concentrate) — Requirement A creature who can cast spells is within 15 feet of the spellvoid Effect The spellvoid feeds on the creature's magic. The spellvoid regains 2d8 healing Hit Points, and the target must attempt a DC 24 Will save. The target is then temporarily immune for 1 hour. **Critical Success** The target is unaffected. **Success** The first time the target Casts a Spell before the start of the spellvoid's next turn, the spell is disrupted unless the target succeeds at a DC 15 Flat check. **Failure** As success, but the effect applies the first time the target Casts a Spell within the next minute. **Critical Failure** As success, but the effect applies each time the target Casts a Spell within the next minute. In addition, the spellvoid doubles the Hit Points it regains.

Go Dark (concentrate) — The will-o'-wisp extinguishes its glow, becoming Invisible. It can end this effect with another use of this action. If it uses its shock attack while invisible, the arc of electricity lets any observer determine its location, making the will-o'-wisp only Hidden to all observers until it moves.