Aether

What is Aether?
Aether is the name for the magical energy that all Elementals possess. If you've ever played any magic based RPG game, it's basically like mana. There's a limited amount for each elemental, some possessing more than others.

Lesser species possess Aether, but it's much more for the healing factor and the fact they need it for the afterlife.

What can it do?
Aether can be used to control the elements, can be focused into certain body parts to enhanced blocks or attacks in physical combat, among other things. It acts as a sort of healing factor for the body, too. I wouldn't really call it a health bar, since it doesn't protect against stuff directly, but it does very much help with physical injuries. Say you break your ankle. The more Aether you have the faster you heal. Aether cannot be increased, but the amount of it required to do things can be decreased with practice.