Zeno is the only Dragon that Yona did not have to go searching for, as he wandered into their camp himself. He is usually cheerful, and though he may seem clumsy, he is actually the most observant person in the group, aware of minute changes or abnormalities. Initially, the group does not understand what his power is, but later, it is revealed that his ability is regeneration, even if he is beheaded or burned alive. This means that he is the original Yellow Dragon who served King Hiryuu. He also admits that he visited the other three dragons when they were children, but he is barely recalled by any of them.

Zeno mostly uses a shield when fighting, to potect Yona and Yoon, who cannot defend themselves, and only uses his ability in dire situations, because it does do his body great harm before his regeneration is activated.