
Well another thing to keep in mind as well is that, whatever Mana is, it is something that can be replenished by drinking a potion (Ether). I suppose however that depending on how you interpret how potions work, it could either be literally giving you more mana, like filling a gas tank, or making your mental acumen stronger so you can focus better (like a mental stimulant). I know some people had different interpretations of how Potions worked as well, such as it either physically healing your wounds, or merely numbing the pain from them.