Dream Nail

Function
Hold down DREAM NAIL to charge and swing the Dream Nail. This can perform several functions:
 * Extract Essence from Ghosts
 * Activate Whispering Roots
 * Collect SOUL from living Enemies (33% meter)
 * Challenge Dream Warriors
 * Challenge Dream Bosses
 * Enter the minds of Dreamers
 * Access the Shrine of Believers
 * Access the White Palace (Awoken Dream Nail)
 * Obtain Void Heart
 * Challenge The Radiance
 * Enter Hidden Dreams
 * Summon The Grimm Troupe
 * Challenge Nightmare King Grimm
 * Access Godhome
 * Read the minds of NPCs, Enemies, some statues and corpses
 * Use to set or travel to a Dream Gate (Requires 900 Essence)

How to Acquire
The Dream Nail is acquired in the Resting Grounds by inspecting the Dreamer Statues. Doing so will send The Knight into a dream where they will receive the Dream Nail from a Moth.

= Awoken Dream Nail = After collecting 1800 Essence, the Dream Nail can be awoken. This allows access to dreams and memories that were previously hidden. The Awoken Dream Nail can be used on the corpse of the Kingsmould in the Palace Grounds. This will grant entry to the White Palace.

Furthermore, the Awoken Dream Nail can be used to view the Dream Nail dialogue of the Shade Cloak creature in The Abyss. This creature has different Dream Nail dialogue depending on whether Void Heart has been obtained.

Essence
Essence is the energy gained from multiple sources after obtaining the Dream Nail. After obtaining certain amounts of Essence, the player can return to the Seer for rewards. A total of 2400 is needed for all in-game rewards and Achievements. Warping using the Dreamgate uses 1 Essence each time.

Essence Sources

 * Using Dream Nail on a Ghost (26 total)
 * Collecting Essence spawned by a Whispering Root (482 total)
 * Defeating a Dream Warrior (1100 total)
 * Defeating a Dream Boss (1000 total)
 * Defeating White Defender (300) and  Grey Prince Zote (300)
 * Regular enemies have a chance to drop Essence:
 * Normal chance: 0.5%
 * Dream Wielder equipped: 1%
 * If Essence was spent: 2%
 * If Essence was spent and Dream Wielder equipped: 4%

Essence rewards from the Seer

 * 100 Essence - Hallownest Seal
 * 200 Essence - Spirits' Glade opens
 * 300 Essence - Pale Ore
 * 500 Essence - Dream Wielder Charm
 * 600 Essence - Attunement Achievement
 * 700 Essence - Vessel Fragment
 * 900 Essence - Dream Gate
 * 1200 Essence - Arcane Egg
 * 1500 Essence - Mask Shard
 * 1800 Essence - Awaken the Dream Nail and unlocks Awakening Achievement
 * 2400 Essence - Ascension Achievement

Trivia

 * The essence gained from passive ghosts are not needed to awaken the Dream Nail.
 * It is unknown whether or not Ghosts are a bug's spirit, a lingering spectre, an imprinted memory, or another form.
 * The Dream Nail can be used to push back most enemies.

Гвоздь грёз Aguijón_Onírico