Writhing

Writhing, also translated as Dark, is a material type introduced in Kingdom Hearts II. Writhing materials contain the essence of darkness, and are colored black.

Design
Writhing materials are represented by black jewels with slight dark green highlights. They have an Elemental material structure.

The material's original name references its dark coloration and the "essence of darkness" it contains.

Drops

 * Dark Shard: Shadow (4%), Soldier (8%)
 * Dark Stone: Assault Rider (12%), Nightwalker (10%)
 * Dark Gem: Gargoyle Knight (10%), Gargoyle Warrior (8%)
 * Dark Crystal: Air Pirate (8%)

Treasures

 * Dark Shard: Chest at the Borough; chest at the Bamboo Grove; chest at the Village Cave; chest at the Rampart; chest at Agrabah.
 * Dark Stone: Chest at the.
 * Dark Gem: Chest at the Gorge.
 * Dark Crystal: Chest at the Corridors; chest at the Canyon.

Drops

 * Writhing Shard: Shadow (8%), Fluttering (8%), Twilight Town
 * Writhing Stone: Shadow (4%), Neoshadow (8%), Fluttering (4%)
 * Writhing Gem: Neoshadow (4%), Fluttering (4%), Helmed Body (8%)
 * Writhing Crystal: Mechanitaur (8%)

Other methods

 * Writhing Shard: Writhing Shard x3 is one of the possible Prize Postcard rewards.
 * Writhing Stone: Writhing Stone x2 is one of the possible Prize Postcard rewards.

Drops

 * Writhing Shard:   ,     ,     ,     ,     ,     ,     ,     ,     ,      (KHII),     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,
 * Writhing Gem:   ,     ,     ,     ,     ,     ,      (KHII),     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,

Rewards

 * Writhing Shard: Clear Twilight Town in World Tour (x18), clear Radiant Garden (KHII) in World Tour (x18).
 * Writhing Gem: Clear The Mysterious Tower in World Tour (x8), clear Crushing Melody in World Tour (x8).

Kingdom Hearts II
Dark materials are used to synthesize the following items:
 * (1 Dark Stone)
 * (1 Dark Stone)
 * (3 Dark Shards)
 * (3 Dark Shards)
 * (3 Dark Crystals)
 * (3 Dark Crystals)
 * (1 Dark Stone)
 * (1 Dark Stone)
 * (1 Dark Shard)
 * (1 Dark Shard)
 * (1 Dark Shard, 1 Dark Stone)
 * (1 Dark Shard, 1 Dark Stone)
 * (1 Dark Gem)
 * (1 Dark Gem)
 * (1 Dark Shard, 1 Dark Stone, 1 Dark Gem, 1 Dark Crystal)
 * (1 Dark Shard, 1 Dark Stone, 1 Dark Gem, 1 Dark Crystal)

Kingdom Hearts III
Writhing materials are used to synthesize the following items:
 * (2 Writhing Shards)
 * (3 Writhing Stones)
 * (3 Writhing Stones)
 * (2 Writhing Crystals)
 * (2 Writhing Gems, 1 Writhing Crystal)
 * (2 Writhing Gems, 1 Writhing Crystal)
 * (5 Writhing Shards, 2 Writhing Stones)
 * (5 Writhing Shards, 2 Writhing Stones)
 * (5 Writhing Stones, 2 Writhing Gems)
 * (5 Writhing Stones, 2 Writhing Gems)
 * (3 Writhing Stones)
 * (1 Writhing Crystal)
 * (3 Writhing Stones)
 * (3 Writhing Gems)
 * (5 Writhing Shard, 3 Writhing Stone, 2 Writhing Gem)

Writhing materials are used to forge the following Keychains:
 * LV5, 6, 8 to 10 (3 Writhing Stones, 3 Writhing Gems, 1 Writhing Crystal total)

Kingdom Hearts Melody of Memory
Writhing materials are used to synthesize the following items:
 * (45 Writhing Gems)
 * (98 Writhing Shards)
 * (44 Writhing Gems, 32 Writhing Shards)
 * (43 Writhing Shards)
 * (20 Writhing Gems)
 * (11 Writhing Shards)
 * (11 Writhing Shards)
 * (11 Writhing Shards)
 * (11 Writhing Shards)
 * (11 Writhing Shards)
 * (5 Writhing Gems)
 * (5 Writhing Gems)
 * (5 Writhing Gems)
 * (5 Writhing Gems)
 * (5 Writhing Gems)
 * (5 Writhing Gems)
 * (17 Writhing Gems)
 * (3 Writhing Shards)
 * (4 Writhing Shards)

Notes and References
Noir Finster