Arc 3The Guardian of the Grail
Mayuri won the Holy Grail War, gained a human body, and rescued Tokiomi and Sakura before settling into life with the Tohsaka Family. Later, summoned as Leviathan to guard the Grail in Singularity F, she watched Chaldea’s group gather allies and then unleashed Leviathan against Medusa’s beasts.
- Artoria renewed her contract with Irisviel, defeated Diarmuid, then fell to Mayuri’s charged attack after releasing four of Excalibur’s seals, while Avalon protected Irisviel.
- Zouken attacked Tokiomi, but Mayuri purified him with holy lightning, entered the Greater Grail, and wished for a real body.
- Mayuri destroyed the Grail to stop Angra Mainyu’s black mud, rescued Tokiomi and Sakura, and left Kayneth to help with the aftermath.
- Mayuri helped Irisviel take Illya from the Einzbern main house, then stayed in Fuyuki as Tokiomi began making amends to Sakura.
- The Counter Force summoned Mayuri to guard the Holy Grail in Singularity F, where she became Leviathan and concealed Lev’s death from Shirou Emiya.
- Ritsuka Fujimaru, Mash, and Olga Marie explored ruined Fuyuki, allied with Cú Chulainn, and met Heracles, who transferred his Spirit Origin into Illya to save her.
- Shirou warned Mayuri that Medusa’s beasts were approaching, so Mayuri unleashed Leviathan, which devoured the beasts, Medusa, and the Holy Grail before returning to its pit.