Like all Kokirins, Nizarah has a pair of nonfunctional wings on his back that expand in stressful situations; his wings appear larger than those of Takaru or Kade. He is tall and slim, but it has been suggested that he was taller when he was younger. (His exact age is uncertain.) For a while, he used a wheelchair to get around after having fallen down the stairs.
Nizarah is conscientious and caring, sometimes to the point of overwork, but not always good at taking the advice of his siblings, who seem to have learnt to put up with his occasional burnouts (although earlier in his life, this led to many disagreements with Six, who believed-- probably correctly-- that he was taking too many risks with his health). It is suggested that unlike his sister Mitori, he can be seriously damaged by physical attacks such as gunshots. For undetermined reasons, Nizarah considers himself responsible for the whereabouts of his sister Posai. He is friendly and tolerant towards Jitai, many of whom live or work at the Feel Better Institute, where he works.
Nizarah is a skilled medic, but aside from conventional medicine, he has the ability to provide a temporary fix for an illness, as demonstrated when he "fixed" Kit's grey skin and bleeding nose. This method is not actually a "cure", however; it works by transferring energy out of Nizarah's system and into the patient's, slowing the symptoms of their illness and buying him more time to figure out the nature of the problem. The process appears to tire him out considerably, and in the interest of Nizarah's health the "loan" of energy needs to be returned at some point. Although Nizarah is somewhat renowned for having "cured" Vee Farren, princess of Tangeltel, of a debilitating sickness when she was a child, it appears that in reality she simply did not live long enough to ever return the energy she borrowed from him.
Intriguingly, Nizarah is so far the only inhabitant of Ui who, while unable to see Kokiro, has not dismissed it as a figment of Kit's imagination. He seems to be actively curious about it, although Kit is reluctant to open up much to him.
In his spare time, Nizarah seems to enjoy growing plants.