God's Right Seat Arc

The God's Right Seat Arc (also referred to as the Vs. Roman Catholic Church Arc) is a long over-arching story cycle in the Toaru Majutsu no Index series. It pertains to stories and events related to the organization known as God's Right Seat.

Starting with Vento of the Front's introduction at the end of La Regina del Mare Adriatico Arc, the arc spans several other arcs and events that occur in the timeline up until the defeat of Fiamma of the Right in World War III. Although not often times directly involved in events and story arcs themselves, their influence and effects on the story can be felt regardless.

The God's Right Seat Arc is the last arc personally named by the author and creator, Kamachi Kazuma in the original light novels. The other being the Dark Side of Academy City Arc that encompasses story arcs related to the science side, and the British Royal Family Arc that encompasses Carissa's rebellion.

Timeline
List of story arcs and events that fall under the God's Right Seat Arc.

La Regina del Mare Adriatico Arc
Introduces the first member of God's Right Seat, Vento of the Front at the end of the arc.
 * Light Novels: Toaru Majutsu no Index Volume 11
 * Anime Episodes: Index II 14, Index II 15, Index II 16

Academy City Invasion Arc
Events of the entire arc triggered by Vento of the Front, and introduces Acqua of the Back and Terra of the Left. Also, references Fiamma of the Right.
 * Light Novels: Toaru Majutsu no Index Volume 12 and Volume 13
 * Anime Episodes: Index II 17, Index II 18, Index II 19, Index II 20, Index II 21 ,Index II 22, Index II 23

Skill-Out Uprising
God's Right Seat does not appear, but their actions in the previous arc has allowed Skill-Out to use the strained Academy City defenses to their advantage.
 * Light Novels: Toaru Majutsu no Index Light Novel Volume SS
 * Anime Episodes: Index II 23, Index II 24

Anglican Church–Russian Orthodox Church Prewar Conference
God's Right Seat does not appear, but their actions in the previous arc has forced a conference between the Anglican Church and the Russian Orthodox Church regarding their possible alliances in the event of a war between the forces of Academy City and the Roman Catholic Church.
 * Light Novels: Toaru Majutsu no Index Light Novel Volume SS

Document of Constantine Arc
The second member of God's Right Seat, Terra of the Left, serves as the major antagonist of this time. Also, Acqua of the Back appears at the end of the arc, alluding that he will be the next to go after the Imagine Breaker.
 * Light Novels: Toaru Majutsu no Index Volume 14
 * Anime Episodes: Index III 1, Index III 2 , Index III 3

Battle Royale Arc
Like the Skill Out Uprising, this arc was indirectly caused by Vento of the Front's attack. The Magic Side characters and Kamijou Touma are absent in this arc, instead focusing on the internal power struggle of the Dark side of Academy City. This clash is allowed to occur due to the Avignon Cleanup Operation, leaving less pressure and monitoring on the groups of the Dark Side.
 * Light Novels: Toaru Majutsu no Index Volume 15
 * Anime Episodes: Index III 4, Index III 5, Index III 6

Acqua of the Back Arc
Events of the entire arc triggered by the third member of God's Right Seat, Acqua of the Back, and marks the first physical appearance of God’s Right Seat leader, Fiamma of the Right. The fate of Vento of the Front is revealed after her failed invasion on Academy City.
 * Light Novels: Toaru Majutsu no Index Volume 16
 * Anime Episodes: Index III 7, Index III 8, Index III 9

British Royal Family Arc
Acqua of the Back reappears, this time as an ally. The end of the civil war is marked with Kamijou's first confrontation with Fiamma of the Right, which will trigger the beginning of the last part of the God's Right Seat Arc and final arc of the Toaru Majutsu no Index light novels. Also, Vento of the Front makes an appearance yet again, on the good side as well.
 * Light Novels: Toaru Majutsu no Index Volume 17 and Volume 18
 * Anime Episodes: Index III 10, Index III 11, Index III 12, Index III 13, Index III 14

DRAGON Arc
The events of the entire arc are set as ramifications of those who survived the Battle Royale Arc coming face to face with their actions, their choices, and their knowledge of discovery. This sets the other two protagonists on course for their roles in the finale of God's Right Seat Arc and conclusion of the Toaru Majutsu no Index light novels.
 * Light Novels: Toaru Majutsu no Index Volume 19
 * Anime Episodes: Index III 15, Index III 16, Index III 17

World War III Arc
The leader and final member of God's Right Seat, Fiamma of the Right, has now sparked a global conflict in order to fulfill his ambitions. He is the major antagonist of this arc and his defeat marks the end of the God's Right Seat Arc.
 * Light Novels: Toaru Majutsu no Index Volume 20, Volume 21 and Volume 22
 * Anime Episodes: Index III 18