Setsuna

Setsuna is the flash flame Dragon. When Setsuna opens his eye, it creates a bright red flare. If one looks into the eye, he will instantly combust and the flames won't die until the target is completely incinerated. 

Source: http://flameofrecca.wikia.com/wiki/Setsuna

Appearance

As a human, Setsuna is blind with a blindfold, numerous blades attached on one hand, and several human eyeballs hanging as a necklace(just beads in the anime). He has blue skin and white hair.
As a dragon, he has four facial marking, and a normally closed eye. He had a slicked back mane of 'hair'.

Personality

Unlike the other dragons, he didn't enjoy being in Recca's body and tried to kill him when the opportunity arose. However, Recca managed to outwit him and forced him back to his body.
When he was alive, he was extremely cruel and killed many people without reason. As a result, he was never named the village head, and his cruelty eventually led him to be killed by his own people; it is unknown if he agreed to produce a child before his death. He was nicknamed 'The Demon Dragon'. 

Abilities

As a dragon, he has the ability Shun-En, which causes anyone that looks into his eye to spontaneously combust and burn until they become ash.
As a human, to cover for his blindness, all of his other senses have been greatly enhanced(which has passed over to his dragon form). He is extremely fast, being the fastest of the flame dragons, and uses a a series of blades strapped to his wrist.