"Oh! Spirits are formed from the dead cores of Entelexeia who are really noble creatures that kept the balance of aer flow in Terca Luminereis. They convert aer into mana for one thing and Undine is the name of one of them that I named myself~ Well I named all of them myself but Undine is a Spirit that governs water~ She was based of a sort of mermaid I've read about~ The name I mean! I thought it fit~" Estelle rambled, cheerful all the while.