Final Fantasy X - Part 44: Dark Shiva

Dark Shiva is summoned by the Guado guarding Macalania Temple. After you defeat her, Guado Guardians will chase you and summon fiends until you leave the area, similar to when you defeated Seymour for the first time. If you head back to the Chamber of the Fayth (8:05), you get a brief scene and a Magic Sphere, Magic Defense Sphere & an Accuracy Sphere but you will have to go through the Cloister of Trials when leaving.