Classification of Divine Beings

The Strength of a Creatures Soul is something that is generally unknowable, but it is fairly well known that a more powerful soul is one that is generally more capable of using magic, and generally more experienced. It is not an expression of worth or of any other measure then pure power. A crude classification system for the tiers of strength that have been observed is compiled here, and most scholarly or governmental institutions would have some version of this.

Mortals

Tier 0

These are considered to be creatures that have souls, but are not particularly attuned to using them and are not trained to use them any great extent besides necessity. This would cover most creatures from CR 0-1/2.

Tier 1

This would cover creatures that are seen by common folk as capable and credible beings. From a full grown grizzly bear to a Lamia, these creatures are powerful on the scale of villages. CR 1-4.

Tier 2

This would cover creatures that are seen by most as serious threats to decent populations. While creatures before this tier could most likely be handled by a full scale militia of small town guards or a true mob of farmers, creatures in this tier are too dangerous. Creatures of this tier would need to be handled by trained/experienced veterans. This would include creatures from Trolls to Hydras. CR 5-8.

Tier 3

This would cover creatures that are seen as nigh-invulnerable by common folk. For humanoids in this CR, this is about the limit non Soul Sparked people can reach relying entirely on only formal practice and training. This is the average extent of a professional, veteran corps. This would include creatures from Fire Giants, to a State's trained Archmages.CR 9-12.

Tier 4.

This would cover creatures that are on the same scale as a natural disaster. For a state, this would be their most elite class: specially chosen warriors for powerful strike teams, Army Generals, Arch Priests, and Archmage leaders. These are creatures the relative strength of an adult dragon. CR13-16

Tier 5

This covers creatures that require the most resources an organized state can provide. From Dragon turtles, Lichs, Ancient Dragons, and Krakens. They are almost too powerful for a nation to take on alone. They usually exist as their own states, dealing equally with entire kingdoms. For humanoids, this would represent the absolute best of the best. These are Legendary Heroes, Emperors, and Champions. This is the limit for creatures without a Divine Spark, showing the the limits of the mortal soul.CR 17-20.

Divine

Only creatures that have obtained a Divine Spark can progress past this point, as it would require power that would destroy a mortal soul alone.

Tier ?- Demigods

A demigod is a creature that pushes the limits of the divine. They do not possess Divine Sparks per say, but they are Divine. The essence of divinity suffuses them Divine traits and making them more than mortal, but does not align them to an Ideal. The Children of Gods are demigods. As they grow, they can actually be weaker than mortal creatures, but they are exceedingly difficult to kill and are not in full control of their abilities, which are unpredictable and vary greatly. This is the intermediary step for any Tier 5 creature wishing to attain Divinity.

Tier 6- Quasi-Deity or Immortals

Immortals are the first class of being that has a fully realized Divine Spark. They are the weakest class of deities, and are subdivided into three groups.
Primes Primes refer to the ideal version of a given type of being. Every type of being from the lowest worm to the sapient species, has at least one Prime deity. Oftentimes they do not even realize they are a Prime being. In most legends, Primes are also the first documented version of that being. Many beast gods fit this category, such as Okku, being the general god of bears, but also being known as the First Bear. Primes have the Ideal of their own types of being or species. They are sustained by the existence of their own species, and thus do not require much in the way of worship.
Paragons Paragons are among the rarest form of Immortal, and refer to beings that have gained a Divine Spark, and aligned with the Ideal of themselves. In the same way that Primes represent their species, Paragons represent only themselves. As such there has never been a known Paragon that has become more powerful, as their Ideal is so centralized. Their sense of identity alone is enough to sustain them, but no more than that.
Vestiges Deities can no longer truly die, they can only be supplanted or forgotten. Without worship, any god can wither away into nothingness, losing themselves in the process. They still exist, but they may reach a point of no return, from which no amount of worship will help restore them. The strength of such a god's body or personal relics are around this level of power.

Tier 7- Deities / Constellations

A Constellation is what people immediately think of when thinking of Divine creatures. Deities are creatures with realized Divine Sparks that have aligned themselves with an Ideal. Upon reaching this rank, their likeness is placed among the stars, to shine forever. They differ from Immortals in that they receive proper, full on worship, with many of them having their own temples, places in pantheons, and roles in various religions. They fit into the following broad categories:
The Old Stars / The Memento Constellations All of the original Constellations have been Deities for as long as they are remembered. Their Ideals are ancient and have been fairly stable throughout the eons.While not every Constellation is worshiped everywhere, they are all respected as powerful. People and nations only draw their ire or disrespect them if they have the backing of another deity at least as powerful as them. They are often included in pantheons, and are present in many religions.
The Constellations All constellations are divine, although to differing degrees, and have achieved their place there in different ways. Many of them are Memento Constellations, older than recorded history, and others have performed great deeds and been placed among them. Prime deities that gain enough worship rise to this rank.

Tier 8- The Powers / Greater Deities

These are the beings that have reached a state more powerful than regular deities. Their Ideals and broad, and encompass almost everything at least a little bit. The Zodiac are the only known Greater Deities at the moment, through the Pochumil ritual granting them an incredible amount of energy from the worship they receive. The Amacruxians are also said to be this powerful on their own.

Player Levels, CR, and Soul Strength

In the world, a player character is assumed to be Soul Sparked, thus allowing them to level and follow the general guidelines of play as described elsewhere. Soul Sparked are rare, only making up about 6% of the population, and levels are spread fairly logarithmically, with low levels being much more common than high levels. A 3rd level character is not unheard of, with a 12 level character being rare, and a 20th Level character being almost unheard of. A Soul Sparked level is not a concrete thing in the world though, as saying you are 10th level would mean nothing to a given NPC. There are simply relative scales of strength. However, CR is a widespread system in the world that scholars and governments would know about and use to mark a character's ability. A rough calculation of your CR is half your Level, with a Level 12 character being roughly capable of handling 2 CR 6 creatures on their own. This is not perfect, but neither is the system in the world.