Foreigner-class version of Mysterious Heroine X. She has three distinct designs depending on her Ascension level:
- Level 1 is her as a mecha musume wearing full armor
- Level 2 loses some of the armor to show her face, and she wears a large blue scarf, skin tight clothes under her armor, and metal gloves and boots
- Level 3 loses the armor completely, and she wears a blue baseball cap, a white bikini, strappy heels, and a blue shrug.
Personality-wise, she's an older, more mature version of Heroine X (and also fills the role of being a swimsuit version of her). She's nowhere near as obsessed as X is with eliminating all the other Sabers, to the point that she sometimes forgets about it completely, and is more focused on eliminating Foreigners. In-universe, she's a Galactic Police officer, but more or less abandons her post to go to Chaldea after the events of the 2018 summer event (2020 for North America).
While her First and Second Ascensions are given character tags, her Third Ascension bikini and shrug is considered her 'default' costume and thus has not been given a tag.