Betwixt

Betwixt, also translated as "Dense", is a material type available in Kingdom Hearts II and Kingdom Hearts III. Betwixt materials contain the essence of In-Between, and are colored grey.

In Kingdom Hearts II, once all Dense materials are obtained, the Moogle will reward Sora with a Serenity Gem.

Design
Betwixt materials are represented by jewels that have an Elemental material structure. They have a dull, opaque grey coloration.

Grey is a color between black and white, which reflects the material's Japanese name, "In-Between". "Dense" can mean "opaque" or "obscure".

Kingdom Hearts II

 * Dense Shard: Creeper (8%), Dragoon (12%)
 * Dense Stone: Sniper (12%)
 * Dense Gem: Samurai (12%)
 * Dense Crystal: Berserker (12%)

Kingdom Hearts III

 * Betwixt Shard: Sniper (18%), Reaper (18%), Olympus, Twilight Town, Kingdom of Corona
 * Betwixt Stone: Sniper (12%), Reaper (12%), Ninja (18%), Kingdom of Corona, Arendelle, The Caribbean
 * Betwixt Gem: Reaper (8%), Ninja (12%), Arendelle, The Caribbean
 * Betwixt Crystal: Ninja (6%), Berserker (73%), The Caribbean

Kingdom Hearts II
Dense materials are used to synthesize the following items:
 * Mythril Shard (1 Dense Stone, 3 Dense Shards)
 * Mythril Stone (1 Dense Stone, 3 Dense Shards)
 * Mythril Gem (1 Dense Crystal, 3 Dense Gems)
 * Mythril Crystal (1 Dense Crystal, 3 Dense Gems)
 * Petit Ribbon (1 Dense Stone, 1 Dense Shard)
 * Ribbon (1 Dense Stone, 1 Dense Shard)
 * Save the Queen (3 Dense Crystals, 5 Dense Gems, 7 Dense Stones, 9 Dense Shards)
 * Save the Queen+ (3 Dense Crystals, 5 Dense Gems, 7 Dense Stones, 9 Dense Shards)
 * Ultima Weapon (1 Dense Crystal)

Kingdom Hearts III
Betwixt materials are used to synthesize the following items:
 * AP Boost (3 Betwixt Shard)
 * Nobody Guard (2 Betwixt Gem)
 * Nobody Guard+ (2 Betwixt Gem)
 * Mythril Shard (1 Betwixt Shard)
 * Mythril Stone (1 Betwixt Stone)
 * Mythril Gem (1 Betwixt Gem)
 * Mythril Crystal (1 Betwixt Crystal)

Notes and references
Mat Duktil