Flukenest

Flukenest is a Charm in Hollow Knight. It replaces the Vengeful Spirit/Shade Soul Spell with a horde of damaging flukes.

Usefulness
Using Flukenest is primarily a preference-based decision, as range and consistency have to be sacrificed for approximately double damage. Flukenest's main advantage is the massively increased damage compared to not having it, which can be helpful for bosses. Likely due to a coding mistake, after a fluke bursts, its hitbox continues to exist for 1 second. Because of this, enemies can be damaged more than once, potentially dealing significant amounts of damage.

Wearing it unlocks extra dialogue with Fluke Hermit.

How to Acquire
Dropped by Flukemarm in the Royal Waterways when defeated.

Trivia

 * This Charm does not damage the Hollow Knight or the Pure Vessel (except when they are in the air).
 * The flukes change appearance depending on the Spell and whether Defender's Crest is equipped.