Tatsuo Mana

A friend of Asaga's who was always sickly with a hereditary disease. As he stayed sick he grew angry with the outside world, he went to Psyren and offered Asaga a card but he refused. In Psyren, he is a figure wearing, holding a rifle that uses his PSI energy. After he kills all but the five survivors, he takes aim at them and destroys part of the building. Amamiya says he's a Burst user and he also uses Rise to fight her physically. After using Trance, Amamiya realizes that Tatsuo was transformed into a Tavoo by having an orb implanted into him. Tatsuo regains his mind after being hit by Ageha's, however his core remains because it is integrated to his body. Because he does not have his card, he stays in Psyren, revealing that he will die when his core runs out of energy, but will look for a way around this. He describes his time as a Taboo as being trapped in someone else's body, and regrets all the killing he did. He appears later on chapter 69 when he saved Asaga from some Taboo. He is later shown with a new Asaga as they are planning to take down a tower. Tatsuo appears again during the W.I.S.E attack on Tenju's Root, riding atop Hiryu's dragon PSI. He uses his gun to poke holes in the dark sky, revealing the sun and causing the Tavoo in the area to disintegrate. (Wikipedia)