AWESOME! That was a super cool mix of alchemy, memorization, resource management, and fighting. It's a concept that works beautifully, and could even be expanded to include four or 5+ elements (with proper systems built to make it more intuitive than rote memorization). Perhaps different methods could be in place for resource collection as well-- loot from enemies, respawning resources, crafting -- I think there is a lot of potential for this idea.