Tannin

Tannin, also known as the Blaze Meteor Dragon, is a former Dragon King who was later reincarnated as an Ultimate-Class Devil by Mephisto Pheles. Tannin possesses a disciplined, warrior-like personality, valuing strength, effort, and perseverance. He has little tolerance for laziness and believes in improving through consistent training and dedication. These traits make him a strict but effective mentor. Unlike many dragons who are portrayed as solitary or self-focused, Tannin shows a strong sense of responsibility and care toward his fellow dragons. His decision to become a Devil was motivated in part by a desire to support and sustain his kind, ensuring their continued survival. He later became involved in the Rating Games, where he rose to the level of an Ultimate-Class Devil and earned recognition as one of the top competitors. With this status, he gained his own territory, which he chose specifically to support the growth of resources important to dragon-kind. He also took an interest in developing methods to sustain those resources more reliably. At some point, Tannin entered a semi-retired role, shifting his focus toward mentoring and training the next generation. Notably, he played a key role in training Issei Hyoudou, helping him better understand and develop his abilities. Earlier in his life, Tannin once challenged Great Red, though the challenge was not acknowledged, highlighting the vast difference in their standing. Overall, Tannin is characterized by his discipline, sense of duty, and commitment to growth, serving as both a respected warrior and a dedicated mentor within the world of dragons.