Wellspring

Energy, also dubbed as "Wellspring", is a material type available in , Kingdom Hearts II, and Kingdom Hearts Birth by Sleep. Energy materials contain the essences of spirit and strength combined, and are colored purple. In Kingdom Hearts, they are used as normal synthesis items, while in Kingdom Hearts II they are "modifier" materials that can be added to a recipe of the same rank to halve the materials needed to make it, and are usable once the Moogle reaches level 2, Novice Moogle. In Kingdom Hearts II, once all Energy materials are obtained the Moogle will reward Sora with a Power Boost.

Design
Energy materials are represented by jewels with a Modifier material structure. They are purple and have jagged, cyan patterns resembling bolts of electricity and swirls of air in them, reflecting the two essences the material contains.

Both the English and Japanese names of this material reflect the electrical bolts in the jewels. "Surging" references power surges that lightning can cause. Lightning is a flow of electric energy.

Kingdom Hearts

 * Power Crystal: Wyvern (2%)

Kingdom Hearts Final Mix introduced the Energy Stone, dropped only by the Stealth Soldier.

Kingdom Hearts II

 * Energy Shard: Bolt Tower (4%), Gargoyle Knight (4%), Gargoyle Warrior (4%), Nightwalker (4%)
 * Energy Stone: Hammer Frame (4%), Lance Soldier (4%), Trick Ghost (4%)
 * Energy Gem: Emerald Blues (4%), Fortuneteller (4%)
 * Energy Crystal: Bookmaster (4%), Shaman (4%)

Kingdom Hearts Birth by Sleep

 * Wellspring Crystal: Scrapper (30-50%), Triple Wrecker (90%).

Kingdom Hearts III

 * Wellspring Shard: Powerwild
 * Wellspring Stone: Neoshadow

Kingdom Hearts Birth by Sleep

 * Terra: chest at the Palace Courtyard, chest at the Launch Deck
 * Ventus: chest at the Hall, chest at the Gates, chest at the Gardens, chest at Pete's Rec Room, chest at the Mysterious Tower, collect 20 points in Ventus's Sticker Album
 * Aqua: chest at the Gates, chest at the Gardens

Kingdom Hearts
Energy materials are used to synthesize the following items:
 * Heartguard (1 Power Crystal)
 * Power Up (1 Power Crystal)
 * Crystal Crown (3 Power Crystal)

Kingdom Hearts Final Mix
Energy materials are used to synthesize the following items:
 * Elixir (1 Power Crystal)
 * Defense Up (1 Power Crystal)
 * Crystal Crown (1 Power Crystal)
 * EXP Bracelet (1 Energy Stone)
 * Fantasista (5 Energy Stone)

Kingdom Hearts II
Energy materials are not listed in any recipe, but an Energy Crystal is required to synthesize the Ultima Weapon.

Kingdom Hearts Birth by Sleep
Wellspring materials are used to add the following abilities:
 * Combo Plus
 * Air Combo Plus
 * Once More

Kingdom Hearts III
Wellspring materials are used to synthesize the following items:
 * Ether (2 Wellspring Shard)
 * Hi-Ether (3 Wellspring Stone)
 * Mega-Ether (3 Wellspring Stone)
 * Elixir (3 Wellspring Crystal)
 * AP Boost (3 Wellspring Stone)
 * Ultima Weapon (2 Wellspring Crystal)
 * Buster Band (1 Wellspring Crystal, 2 Wellspring Gem)
 * Blazing Crystal (1 Wellspring Crystal)
 * Frost Crystal (1 Wellspring Crystal)
 * Lightning Crystal (1 Wellspring Crystal)
 * Lucid Crystal (1 Wellspring Crystal)
 * Pulsing Crystal (1 Wellspring Crystal)
 * Writhing Crystal (1 Wellspring Crystal)
 * Soothing Crystal (1 Wellspring Crystal)

Notes and References
Fougue