1515. Accepting Nature's Guidance
Mana was something that literally made up an elemental spirit. However, they were more than that. At some point, they used the elemental mana that made them create something more. Something that powered every living being above even natural mana.
This became the voice they gained. The voice they learned to use with the elemental mana. The voice that allowed them to speak with other elemental spirits and become stronger. Finding such a voice was rare but many of the older high elemental spirits had it.
The next step would be for a high elemental spirit to become a grand elemental spirit. Something that could require a lot of time and elemental mana of a specific kind. Or, it could require something more. Something that improved this thing that made them intelligent.
They would need a stronger soul.