Isahaya

Isahaya (諫早) is a member of the Amakusa-Style Remix of Church and Itsuwa's grandfather.

Toaru Majutsu no Index
In the anime he can be spotted in fourth episode of season 2 fighting the Agnese Forces.

Acqua of the Back Arc
Isahaya is present with the rest of the Amakusa as they spy on Itsuwa and Touma from behind a nearby building. He and the rest of the men gather around Tatemiya Saiji as he describes Itsuwa's greatest weapon which she has yet to use, seemingly pleased at how his granddaughter has grown up. He is slightly concerned at her lack of progress with Touma due to being too passive.

Abilities
His main weapon is a mace.