Prior to the formation of the universe, there were three raw cosmic elements. The first was the Primordial Cage, within it was housed the other two, the Cosmic Blood and the Soul Mass.
The Primordial Cage was a sphere that housed the Cosmic Blood and Soul Mass. It was the egg that gave life to the universe, since the turmoil within the Primordial Cage eventually shattered its walls, and so began the Genesis. It is considered to be the purest form of matter, it has no attributes of energy, magical or otherwise, with the exception of its own unique form of magnetism and it can only be charged by an equally pure form of energy. In other terms, the Primordial Cage cannot be affected by magic or normal forms of energy, in fact, it is capable of dispelling magic and energy. When the Primordial Cage was shattered during the Genesis some shards turned into dust and formed around planes, realms and dimensions, creating a barrier between fundamentally different parts of the universe, a barrier now referred to as the fabric of reality. Without the fabric of reality these different spaces of existence could meld or violently react with each other undoing the universe. The shattered shards of the Primordial Cage are now simply referred to as primordial iron or primordite.
The Cosmic Blood is the raw power of the universe, it is the source of both magic and all natural elements, and due to this shared origin, the natural world can be manipulated through magic. It was this raw power that created Planes, Realms, Worlds and Dimensions. The Cosmic Blood is invisible and intangible to most when not being used as magic; however, it is spread throughout the universe similarily to how veins are spread throughout a body. Due to it reaching every corner of the universe, the veins of Cosmic Blood can be used as roads to navigate the cosmos and traverse between space and time.
The Soul Mass was instrumental in starting the Genesis, and though it didn't directly define the universe like the shards of the Primordial Cage and Cosmic Blood, it did have a substantial part in changing the universe through creating life and death, it brought into existence beings of great power who were capable of manipulating the very universe. The Soul Mass was the collection of all the souls that existed before the Genesis, due to the fluctuating nature of the Souls Mass, the number of souls was constantly changing. This building chaos was what finally led to the rending of the Primordial Cage. As stated previously, the Soul Mass is exactly that, a mass of souls; however, with the formation of life came two other entities, spirits and mors.
When the Primordial Cage shattered the Soul Mass became tainted by the power of the Cosmic Blood, this allowed souls to become the essence of life, since through their power flesh could be formed from the natural elements created by the Cosmic Blood. Exceptionally powerful souls formed life without flesh, these lifeforms are the Theoi, beings considered deities. When a new life starts, a soul will spawn a spirit, which is the essence of that life, it holds the memories, personality, power, and various other marks and attributes of that life. When the being dies the soul leaves the body but remains tethered to the spirit, eventually, that soul may start a new life and spawn a new spirit, creating a web of spirits through many incarnations. When a being dies, the separation of the body and soul creates a Mors, a death spirit.
As previously mentioned, spirits are an accumulation of a being's life in the form of an ethereal manifestation of a soul. Unlike souls, spirits without a body can freely interact with most aspects of the physical world if they're powerful enough; however, most are drawn to other realms which are shaped to house spirits, such as Hel
Mors are similar to Spirits in many ways, they even hold some attributes of the being they came from; however, they are only spawned when an individual dies. While Mors are also tethered to the souls from which they originated, it is possible for the bond to be broken, and since Mors have a weaker will and are typically not self-aware, they can be manipulated, making them the key to bridging the gap between life and death through necromancy.
The Cosmic Elements are universal, they can't be changed and can be encountered anywhere in the universe.