The basic of the scale is a 1-10 scale:
3 is "this is the average capacity of a human". 5 is "this is the typical peak level of a human". 10 is "this is the typical peak superhuman level". * is "this is the peak level a spirit can reach". (Spirits, notably, are at their strongest, above superhuman which makes sense considering they're not human at all. Though, that being said. Not all spirits are above superhuman in all areas. In fact, none are. And many aren't even above superhuman in any. Still, they have the capacity to be higher than superhuman, thus the ranking.)
** is "god-tiered", as in, if a god were to manifest, this is the expected power level they would have.
*** is "godslayer", as in, if a god were to manifest, this is the level of power necessary to kill said god.
This metric is meant as a guideline. Not an absolute rule. It is not explicit word of god, so much as it would be to give a fair idea for what sorts of things are, and are not, possible. A reference point, but not an absolute reference point; a loose reference point for generalities, a way of being able to give some sort of comparison between things which you would normally never be able to compare otherwise.
There are sixteen categories which you can apply this scale on.
Strength: Self-explanatory. How strong someone is. Physical power. Might. Oomph to their punch. How much they can lift. How hard they hit. You get the idea.
Speed: Self-explanatory. How fast someone is. Note that this is unspecific as to the type of speed. So this is a bit of a broad category, but loosely, it can be thought of as "how rapidly you can act/react".
Agility: This is also fairly self-explanatory. This is how nimble someone is. Their maneuverability in combat. Able to jump over someone, spin, run circles around them, bend limbs in unusual ways. Their flexibility. Their ability to move around in a controlled fashion and know precisely where they are going and what they are doing. How precise they are in their movements.
Stamina: This is how long someone can go. Their physical energy reserves; how long they can continue to fight. This covers both the physical and mental aspects of it. It is how long it takes you to become exhausted.
Endurance: This is how much punishment you can take. This is not toughness; this is not stamina. This is the opposite of both, in that this is how much damage you can receive, and yet not collapse. It is, essentially, how unfazed you are by the damage you take. If you have high endurance, then sure the blows you take can break bones and cause internal bleeding, but you can keep going.
It is your ability to resist pain. It is your ability to push through the hardships of battle. It is not based on how much energy you have; it is not based on how resistant you are. It is based on fortitude, on willpower, on how well you can sustain yourself in battle when you are being continuously beaten down. (It is thus, notably, a common heroic trait.)
Toughness: This is your ability to tank damage. Or rather. This is, specifically, how hard it is to damage you. Someone whose skin is like armor? That's superhuman toughness. Someone who you can cut through as if with a butterknife? That's low toughness. Easily damaged, fragile, low toughness. Hard to inflict any harm at all, hard to damage, high toughness.
Basically, toughness is how hard it is to damage you, whereas endurance is how much damage you can take before you collapse. That should give you the difference between the two. Stamina is how much you can put out before collapsing.
Regeneration: How rapidly you recover from damage inflicted. 10 would be something like regenerating lost limbs to give a general frame of reference. This is a fairly self-explanatory concept. Humans have wounds which heal fairly slowly comparatively speaking compared to the supernatural entities in existence.
Recovery: How rapidly your energy reserves are replenished. High recovery can lead to someone who ran out of stamina ending up still being fresh in the middle of a battle, for instance; low recovery means that what you put out in the battle is it, and maybe then some with it taking a long time after the battle to recover what was lost in it.
Intellect: Basically how smart you are. This covers all aspects of smartness, from improvisation to planning, from intuitively picking things up to meticulous analysis, from understanding how things work to applying the optimal usage of what you have. This is usually a constant, based widely on the individual rather than the species, but there are some exceptions where beings have the ability to temporarily up their intellect (or in some even rarer cases, where entities sacrifice intellect for greater gains elsewhere), thus its inclusion.
Then come the magical equivalents to these stats.
Magical Power: How strong your magic is. For reference, Phyrra and Cyrus went from 0 (had none) to 10 overnight. 3 is the level of an established fullblown mage. Accomplished spellbladers are 2s; amateur spellbladers--even prodigies--are 1; this is the level that both Clara and Cedrick are at.
Yes, 1. Spellbladery is, as I have previously established, akin to using a single finger from a single hand instead of a full arm yet alone the full body. And Paladins are spellbladers; Cedrick's telekinetic control over his platinum spheres is a type of spellbladery.
Magic Casting Time: How rapidly you can cast/control your spells. Phyrra and Cyrus also went from 0 to 10 on this overnight. In contrast to Magical Power, this is actually an area where spellbladers tend to actually exceed the levels of mages.
After all, mages use a wide variety of magic; spellbladers specialize in a specific type of magic, so it makes sense that, naturally, spellbladers are going to be very good at their specific magic. Cedrick is a 5; Clara is a 4.
Magic Versatility: This is a combination of how diverse your magic is and how skilled you are at applying your magic to different types of situations. The former would lock spellbladers at 1 (because, obviously, they can only do one thing), but the latter--how creatively you use your magic--allows spellbladers to, potentially, reach slightly higher levels. (Because if you're gonna only do one thing, you get very good at learning how to use that one thing in creative ways.)
Phyrra and Cyrus went from 0 to 10 in this as well. (Note that, for all three of these, their 10 is 'potentially at this level', not necessarily 'is guaranteed to be at this level'. Phyrra and Cyrus have the potential to cast the most powerful spells in the least amount of time which can be literally any type of spell...but they have to train themselves to do that, first.)
Cedrick is actually fairly low on this, as a 2; Clara is a bit higher, as a 3, because Paladins are one of the most advanced form of spellbladery.
Magical Reservoir: This is basically the amount of magic you can cast before collapsing from exhaustion/potentially killing yourself. Phyrra and Cyrus went from 0 to a potential 10, but their bodies are unaccustomed to this level of power so their bodies have been slowly adjusting their way up. Pragmatically they start at around 3: average human capabilities. As the story progresses, they can tap into more and more magic, allowing them to use more and more and make bigger and bigger things. (Because the more powerful the magic, the more it taps into the magical reservoir, obviously.)
Cedrick is around a 2; Clara is around 4.
This is thus the magical equivalent of stamina.
Magical Resilience: How much magical punishment you can take. Humans are notoriously low on this compared to spirits. This is the equivalent of endurance for magic.
Magical Resistance: How much magical damage is reduced. Very few beings, even spirits, have higher ratings on this, except for beings which have resonance with anti-magic (which is a thing, kind-of; it'd be more accurate to say magical reduction because you can't get rid of magic altogether).
It is thus the magical equivalent of toughness.
And last but not least:
Magical Replenishment: How rapidly you recover your magical reservoir to cast spells. Phyrra and Cyrus go from 0 to theoretically 10. Like with the reservoir, they start unaccustomed to their full potential, with their bodies slowly adjusting their way up. Pragmatically, they start at around 5: exceptionally fast for humans to recover, but still at notably human levels of recovering, so no unlimited casting of spells continuously.
Cedrick is around a 4; Clara is around a 2, maybe 3.
Soyeah, that's the system I devised. From the descriptions I've given, you can probably already get a good sense of why I emphasized this is not an exact science. It's just a loose reference point for about what level characters can and can't do.
And that's about all I can say because I'm pretty sure my computer's gonna try and restart again literally any second now. Every second is pushing it, but one last thing before I go.
I'd like to say today is my one-year anniversary with my girlfriend, and I wanted to share that with the world. <3