Fiamma of the Right is the leader of God's Right Seat and the main antagonist of the magic side in the Toaru Majutsu no Index Light Novels. His name is derived from the Italian name for flame, "Fiamma."

Among the members of God's Right Seat, he is seen as the highest position, and the other members are shown to be more loyal to him than they are to the Pope. Behind his calm personality hides a manipulative and ambitious person who doesn't hesitate to overstep his bounds past the authority of the Roman Catholic Church, use the entirety of Russian Orthodox Church, and even declare war against Academy City.

The leader and center of God's Right Seat, with him stating as long as he's alive, the positions of Acqua, Terra and Vento can be replaced, but if he's gone God's Right Seat as an organization would also be gone beyond salvaging.

He seeks Touma and Index, the former for his power, which Fiamma considers the Holy Right, and the latter for her knowledge in inaccessible forms of magic. Fiamma also uses his status as the current Pope's mentor to classify Touma as a heretic, thus enabling him to fulfill his purpose to capture Touma. He holds enough power to blow away all of Rome in one blast, but 2/3 of the damage is avoided by the Pope absorbing it to protect the city, resulting in the Pope being hospitalized; however, part of the Vatican was still damaged by the attack.

Fiamma created a monstrous flying fortress named Star of Bethlehem in order to complete his ritual to save the world. It was constructed by taking some useful parts of religious building like church or cathedral from all over the world. He easily swept off both of Russian and Academy City army during the war and made him controlling the war. However this action was just becoming a boomerang to him because all of the remaining forces decided to take him down. Even the Roman Catholic Church, Russian Orthodox Church and Anglican Church that had been in conflict also decided to join the force and beat him down.

Finally, with magic that constructed from Roman, Russian and Anglican spell, The Star of Bethlehem was crumbling down. Kamijou Touma easily punched the powerless Fiamma of the Right and destructed all of his spell. Fortunately, instead of letting he die along the destructed fortress, Kamijou Touma decided to save him by putting his unmoved body in the escaping container. He stuck in the snowy land of Russia and met up Aleister Crowley. Aleister mocked his plan and trod him as a enemy. The he cut his arm off and let him die in the deep of snow.

Seems that he still managed to live and he was saved by a former candidate of Magic God named Ollerus.