What are inhabitants of the universe of Erthos

Two different sentient inhabitants exist in Erthos, the Spirits, and the Mortal Races.   As a rule, the Spirits are rigid in their essence, never changing in their traits. Some of these Spirits, The Chara Spirits, have gained enough Essence to be worshipped by other creatures. They are the embodiment of their domains. Once a Spirit gains this much Essence, they are able to share with their worshipers, which allows them to mark the Essence of their Followers as their own. Each of these Spirits belongs to a Pantheon; while not being a rigid organization, they often are linked to one another. There is usually one Spirit who has the most Essence in the Patheon and the others heed their commands. For example the Patheon of Magic is ruled by Brunus "Lord of Magic": Spirit of Magic and the Patheon of Chaos is ruled by Anador "Spirit of Chaos"  The Chios Spirits are immortal spirits that similarly to Chara Spirits, embody a trait, but not nearly as much as Chara Spirits too. Some of the Chios Spirits have their own forms because they have gained enough Essence to stand out from the other Chios Spirits. All Spirits have limited Essence and are constantly seeking ways to gain more to have more power. They accomplish this by being worshiped by Mortals, claiming the Spirits of Mortals once they die, and by killing enemies and claiming their Essence.
There are a few different classifications of Spirits, such as Fiend Spirits and Undead Spirits.   Fiend Spirits are malicious creatures who can only be slain on their home plane of existence. These creatures are constantly striving to take Essence from others and grow in strength.   Undead Spirits are spirits who did not pass on to the Eternal Domain; and some scholars believe that they can not truly be killed. When a mortal creature dies and their spirit is trapped to become an Undead Spirit they inhabit their corpse and reanimate it, or take another form. These Spirits are generally not found in the Eternal Domain.
Mortal Races are ever-changing based on their life experiences in the Mortal Realm. This helps decide what they become once they pass on to the Eternal Domain. Once they die on the Mortal Realm their Essence passes on to the Eternal Domain and takes the shape of whatever they embodied in life. Mortal Races are wellsprings of Essense; it grows and thrives within them.   Non-sentient creatures live in the Mortal Realm. If they survive long enough, they may grow sentient as their essence increases.