Most humans are pureblood humans, which are humans with less than 25% sura blood. Purebloods have the shortest natural lifespans of any of the races. Pureblood humans have identical eye and hair color, though subtle variations have been seen in Asha Rahiro, Lorraine Rartia, and Anna Haias.
Pureblood humans were born after the nastikas and the astikas, and lived with them until the Cataclysm. Until that time, they occasionally had relationships with suras and were able to conceive children with them, which were called Halfs or Quarters according to their amount of sura blood. The primeval god Brahma created the barrier and checkpoint systems to protect their main cities from sura attacks. Many purebloods are prejudiced against and shun Halfs due to the effects of emotional resonance during the Cataclysm.
In the distant past, humans were able to draw power from both gods (divine magic) and suras (fiendish magic). After humans ended their connection with the suras and the gods made humans promise to borrow power only from them, there remained communities that continued to worship suras, such as the village where Ian Rajof grew up; these humans were considered heretics.
After the Cataclysm, divine magic was considerably weakened. The summoning rules themselves changed, making humans risk their own lives to summon a god with the Idha Etu magic.
The barriers, no longer empowered by gods, weakened. Now, only a priest with the corresponding triple attribute can maintain a barrier without risking his or her life; only Asha Rahiro is able to change a barrier's attribute.
Purebloods are known to have a low vigor threshold, but regenerate vigor faster than any of the other races. Humans are also the weakest when it comes to physical strength. Purebloods can use magic since they have the highest divine affinity of the three types of humans, but they also have low transcendental values; thus they are not able to use transcendental skills (with the exceptions being Rao Leez and Kubera Leez).