Monster Analysis: Will-o'-Wisps

  • Encounter Appearance: 2-15 Where the River Goes
  • Armor Class 19
  • Speed 50 ft flying (hover)
  • Darkvision 120 ft, passive 12
  • Resistant to acid, cold, necrotic, thunder, and nonmagical physical weapon damage
  • Immune to lightning and poison damage
  • Immune to exhaustion, grappled, paralyzed, poisoned, prone, restrained, and unconscious
  • Suggested Average, Max HP: 22, 36
    • Temporarily dispatched by Nott with 28 damage strike

Though they may look like bright, hopeful lights, will-o’-wisps are tiny, evil undead. Often created when an evil individual is killed in anguish in places of powerful magic, wisps relish the schadenfreude of causing other creatures’ miserable deaths. This hateful origin, coupled with the notes Caleb read in the lab, gives us a glimpse into how these wisps ended up in the urns of the abandoned laboratory in the first place: vile souls who met their gruesome ends and were anchored here as cruel guardians.

Will-o’-wisps move alarmingly quickly, weaving with the same rapidity of the lightning they deal. After the three of them shocked Molly, Nott, and Fjord for 8, 12, and 10 lightning damage respectively, Jester cast Sanctuary on Nott so the goblin wouldn’t take any more damage after already hurting from the trapped hallway downstairs.

The wisps’ ghostly nature makes the majority of the few attacks that manage to make contact deal only half as much damage as usual, if any. The only members of the party capable of dealing non-resisted damage in a straight fight were Fjord (with his magical Wastehunter Blade or the force of Eldritch Blast), Caleb (with fire damage spells), Molly (Rite of the Dawn), and Jester (Spiritual Weapon). Nott and Beau both landed hits on the creatures, but the nonmagical nature of their attacks meant that the wisps only took half damage.

Fortunately for the Mighty Nein, the key to fighting these particular will-o’-wisps was first hinted at when Nott killed the one that came at Yasha, when its light motes reformed in a nearby urn shortly after appearing to initially fade. Thanks to Molly’s experiment against the pottery, Caleb turned his attention to the much more easily accessible and fragile urns, ending the will-o’-wisps undeath cycle with a series of Scorching Rays and an impressive final pose.