Also known as: レディ・アヴァロン
A swimsuit version of the Merlin (Fate/Prototype) from Fate/Prototype, appearing in the summer 2022 event of Fate/Grand Order as a Pretender-class servant. She goes by the name Lady Avalon as an alias, and pretends to be the male Merlin (Fate)'s younger sister.
Character Design: Taiki (Luster)
Voice Actress: Kawasumi Ayako