Ucchusma has the appearance of a giant blazing bird. He is roughly five times larger than a normal human, and is surrounded by red flames. His head, which is concealed in a bird-like helm, is decorated with eyes with ring patterns in them. Each eye is located on either side of his large beak, while a third eye is located on the top of the helm. On the back of the helm are two feathers that jut out on each side. Ucchusma's neck is covered in bands attached to clasp-like structures on his chest. On his chest are circular patterns similar to the eyes on his helm. The "eyes" are located on each side of his chest, as well as in the center. Lines running along and across the torso divide it into upper and lower sections. The lower part of Ucchusma's body ends in flames that narrow into a reverse triangle.
Ucchusma appears to be stern and inconsiderate at first but then understands the situation involving the Impure King and lends its powers to Rin . When time came to defeat the Impure King, Ucchusma points out that burning down the whole region influenced by the rot of the Impure King (which would involve unrequired deaths of people) is a small sacrifice. It was Rin's control over the flames that saved everyone and only purified the region rather than destroying it.
It dislikes humans because they often mistake it for Karura.
Impure King Revival arc
He appears for the first time when Shura, Yaozo, Shima and other Upper Class Tamers summon him and request his aid. After Yaozo presents him with the blood signatures of five High Priests, Ucchusma rejects the offering and states that "Five is too measly". The Demon then decides to bless the Exorcists with his divine flames because he doesn't like the idea that the Impure King can act as it sees fit. At this very moment, the Khakkara wielded by Exorcists of the Shima family become engulfed in flames and they all charge into battle against the Impure King. Ucchusma also gives his flames to Renzo when he came back, after running away, to help Konekemaru, setting Renzo's Khakkara ablaze. The kin of Iblis makes his latest appearance when Rin needs help in defeating the Impure King. He shouts that he's "A pain to look at" and when Rin asks if he's a Demon, he seems insulted and says that Demons are only a name that the humans gave them (similar to angels). Ucchusma seems surprised to see a human wielding 'holy flames'. He tells Rin that he will help him in defeating the Impure King and says that he'll teach him how to control his Blue Flames. Ucchusma then possesses the Kōmaken, engulfing the sacred sword with flames, and launches himself out of the blade towards the Impure King in a smaller-sized version of himself. As he flies towards the kin of Astaroth, Ucchusma orders Rin to repeat the chants and sutras that he will utter.
Powers & Abilities
Kōmaken equipped with Ucchusma
While Ucchusma has not been seen in battle by himself, he is implied to be just as strong as his rival, the Impure King. He has the power to augment the flames of Satan through attaching himself to Rin's Kōmaken. He does this by transforming into a diminished version of himself. In this form, Ucchusma is able to greatly increase the destructive power and range of his flames to the point where, in conjunction with Rin's own power, the two are able to create enough flames to cover an entire mountain. While Rin is able to alter the power of the flames to only purify and burn the Impure King's bacteria, Ucchusma implies that his power is able to destroy all the living creatures on the mountain.
- (To Rin Okumura) "Demon, Angel, Vidyaraja... There're all just names humans decided to give us. Who are you to call me like that?"
- (To Rin Okumura) "I wonder which one you are. A human...or a Demon? One day you will have to decide."