Here is a complete list of the current valid elements:
Here is the list of elements you can choose for your characters mastery, weapons, spells, forms, summons, and enchantments. If you see a key element missing, just post what you think should be added here.
The Elements:
-Nothingness
-Space*
-Wind
-Ice
-Earth
-Illusion*
-Moon
-Fire
-Water
-Time*
-Rose/Flower
-Thunder
-Cure
-Darkness
-Light
-Metal
-Molten
-Ink
[b]* Denotes a forbidden element
Credits: Kingdom Hearts
Please keep in mind that god-modding rules are still in use. Some of the powerful elements like Time, Space, and Illusion cannot be abused for something such as invisibility or time freezing and launching your opponent into the atmosphere, etc. You probably get the point. These elements should be used as your character's primary, secondary, and tertiary elements.