For people of this world, the elements are the method of advancing, and growing stronger.  There are seven ranks within each realm.  The middle ranks are notorious for being difficult to advance through. The sixth rank requires twice as much elemental essence to advance into the seventh, but cultivators require twice that much again in order to make the attempt to assault the boundary to the next realm.

Elemental Sensing, and Absorption is the basic beginner where a cultivator learns of existence, and embarks onto a lifetime struggle to grow, and evolve.

Foundation Realm - First Realm of advanced existence, where the cultivator uses their absorbed elements to rebuild their foundation into an extremely dense and thick material.

Junior Core Realm - A small core of their Primal Element is used to build a core similar to a beast core.  This is now their elemental storage for immediate use, as well as the medium to access their reserves.

Core Realm, Adult - A full sized core of the cultivator's Primal Base Element, and the basis for future growth.  If the Foundation is not strong enough, it will crumble, and cause a backlash that will waste their cultivation.  They will never be able to rebuild their Foundation before they become too aged to advance again.

Free Core - A full core freed from the resting place of their foundation, but tied by elemental essence to their elemental void space, where their reserve essence is stored.

Ascended Human - The cultivator's Primal Core, freed of the foundation, ascends into the void space, and becomes an elemental gemstone.  The potential for growth increases dramatically.

Human Demi - Half immortal, with a human body, but houses the void space of the children of the stars.  Not a god, but a good imitation for mortal existences.  No longer ages, and is immune to disease.  No known humans have advanced into this realm.

Divine Demi - A child of the stars. Their void space is now incredibly huge, and the source of their vast power, once a small elemental essence core, is now the size of a moon.

The universe will not allow further insights into the existence of the divine.  The one to whom it belongs has not yet taken their place.

The true nature of cultivation within the universe Aila traveled to was that it was not Dao, Spirit, and Qi like in novels she had once read.

All existence within the universe was built with the elements, in either the material form, such as stone and metal, or the immaterial form, such as fire, light, dark, life, and death.

Aila does not increase in power by following the common knowledge of the world.  She is a rule unto herself, and has not advanced, or climbed through the ranks, or from one realm into another.

She is the Elemental Existence the universe has provided for itself.