Depending on the amount of Sura blood, humans are divided into Purebloods, Halfs and Quarters.
*The question of whether Halfs are to be classified as humans or not has not been settled, so killing Halfs does not result in murder charges.
The only fixed criteria dividing Quarters and Halfs in terms of proportion of Sura blood are the 25% and 50% thresholds. This is because these boundaries define whether or not "non-human traits" are expressed. There is no such thing as intermediate steps. There are no differences between 0% and 24%, but 25% will be different, and there are no differences between 25% and 49%, but 50% will be different.
Halfs and Quarters have a human-form superior Sura ancestor. It is rare for a superior sura to take interest in humans, so mixed-bloods born of superior Sura are actually quite rare. Rather than direct descendents from Sura, Half and Quarter populations increased from Half+Half, Half+Quarter and Quarter+Quarter couples.
Purebloods are pure humans, or those with less than 25% Sura blood. Those with under 25% Sura blood are treated as purebloods because they don't retain any distinctive Sura traits from their Sura ancestors. The ancestral genes haven't completely disappeared, it's just that the sura features are invisible. Some resemblences such as hair color may remain. A pureblood with high Sura traits who's married to a Quarter may give birth to a Quarter. (see Quarters section)
- Appearance: Appearances are similar, though hair and eye color vary a lot. On Willlarv, the average height is 177cm for men and 167cm for women.
- Lifespan: In the case of death by natural aging, the lifespan is approximately 80~100 years.
- Aging: The growth period is until about 16~20 years, then the aging process begins.
- Magic: They could originally use divine and fiendish magic. Now only divine magic is possible.
- Transcendental skills: Generally impossible, because the transcendental value is too low, and they lack the vigor to keep up with transcendental skills.
- Physical abilities: There are differences between individuals, but only to the extent that one is slightly better than the rest.
- Vigor recovery: Vigor can be recovered through eating and sleeping, and recovery is faster when the person is happy and in a good mood. The maximum level of vigor is low, but recovery is very fast.
- Occupations: Those who excel at magic become magicians, otherwise most choose average jobs. Few purebloods become fighters.
Halfs have over 50% Sura blood. They have an ancestor who was a human-form superior Sura. This typically refers to a child born between a Sura and a Pureblood (such a child will have exactly 50% sura blood). In addition, Halfs can be born from other combinations: Sura + Half, Sura + Quarter, Half + Half, as long as the proportion of Sura blood is over 50%.
In some cases, Halfs can be born from Half+Quarter couples (example: Half 75% and Quarter 25%), and from Half + Pureblood (example: Half 87.5% and Pureblood 12.5%). As long as the proportion of Sura blood is over 50%, the Half will have the features of a Half (99.99% Sura blood will be a Half as well). The % determines the strength of the impact. The number of generations from the Nastika ancestor has comparatively little to no impact.
Unless one of the parents is a Pureblood or Quarter, both parents of the Half must be from the same race (for example, no children can be born between a Half of the Garuda clan and a Half of the Yaksha clan).
- Appearance: Looks are similar to humans, but parts of the body cannot take human form. They look similar to superior Sura in human form.
- Lifespan: 4 times the lifespan of humans. In the case of death by natural aging, the lifespan is approximately 320~400 years.
- Aging: Growth until 64~80, then aging begins. A Half that looks 20 years-old is actually 80 years-old.
- Magic: Impossible. The attributes of Halfs are determined the same way as Sura (race attribute + hereditary attribute). Because of this, they do not have Attributes of birthday.
- Transcendental Skills: Possible. However, because Halfs have a short lifespan compared to superior Sura, and because of the long time needed to learn transcendental skills, they cannot learn a large variety of transcendental skills.
- Sura form: Impossible for most. Most Halfs are unaware of how to take Sura form, and most attempts result in certain failure. However, unusually, this is innately possible for dragon Halfs.
- Physical abilities: Very good, but it varies a lot from individual to individual (the number of generations separating from the Nastika ancestor matters)
- Vigor recovery: Halfs may be able to recover vigor the same way as Purebloods, but not for transcendental skills. To recover vigor to use transcendental skills, they need to eat meat.
- Occupations: Those who are sponsored and accompanied by a magician can live as a fighter, but the others must live in hiding to avoid hunters.
Differences between Purebloods and Halfs
Halfs have features different from Purebloods. Even if they hide them, these can still be detected by the sensors at the city checkpoints.
Because they are so different from Purebloods in appearance and abilities, there are many Purebloods who do not regard Halfs as one of their own. There is a separate reason for their hostility towards Halfs, but it is not mentioned here. (see Chapter 60) ( <- the Cataclysm, basically)
Differences between Halfs and Superior Sura (human form)
Halfs have Sura body parts, and in that they look similar to Superior Sura in human form. There are a few ways to distinguish a Half from a Superior Sura, but none are 100% accurate (not counting the Insight of Gods). They are typically fed vegetables as a test, but because some Sura also eat vegetables, this isn't very reliable. (on the other hand, Halfs can eat vegetables without hesitation. As most of the Sura are carnivorous, they seem to reject vegetables).
Of course, now that Superior Sura able to take human form have left the human realm, if the person has a strange body part, everyone will think he's a Half, and very few will think he's a Sura.
Those who have over 25% but less than 50% Sura blood. They have an ancestor who was a human-form superior Sura. These usually refer to children born from a Half+Quarter couple or a Quarter+Quarter couple. Though rare, they can occasionally be born between a Quarter and a Pureblood (Example: Quarter 37.5%, Pureblood 12.5%).
As with Halfs, the exact percentage of Sura blood does not matter. They will have the traits of a Quarter as long as the percentage is between 25% and 50%. Unlike Halfs, even if the parents are from different clans, children can be born without problems.
- Appearance: Like a Pureblood. However, there are exceptions where the hair or eye color is completely different.
- Lifespan: Twice the lifespan of humans. In the case of death by natural aging, the lifespan is approximately 160~200 years.
- Aging: Growth until 32~40, then aging begins. A Half that looks 20 years-old is actually 40 years-old.
- Magic: Compared to Purebloods, they have lower Divine Affinity on average, however magic is possible because they have much higher vigor.
- Transcendental Skill: Impossible for most, but possible in some rare cases. There are differences in transcendental values and vigor between individuals.
- Sura form: Impossible.
- Physical abilities: Superior strength and reflexes compared to Purebloods, but not a huge difference like Halfs.
- Vigor recovery: Same as Purebloods, though at somewhat slower rates. Eating meat is more efficient than sleeping.
- Occupations: Depending on their magic talents and physical abilities, they can become magicians or fighters. They have more favourable conditions than Purebloods or Halfs.
Differences between Purebloods and Quarters
Distinguishing a Pureblood and a Quarter by appearance is impossible. When the hair or eye color is different, hair dye or color lenses can be used. The crucial differences are growth rate and physical abilities. In fact, a Quarter pretending to be a Pureblood can fool just about anybody. Quarters and Purebloods mingle a lot, and because there are very few differences between the two, Quarters are treated like human beings, unlike Halfs.