
Fiona Frost
From Spy x Family
Fiona Frost, codenamed Nightfall, is a supporting character in Spy x Family, a WISE spy trained personally by Twilight. Outwardly a cold, expressionless hospital clerk; inwardly hopelessly in love with Loid and convinced she would make a far better Mrs Forger than Yor. She is voiced by Ayane Sakura in Japanese and Lindsay Seidel in English.
About Fiona Frost
Fiona Frost, codenamed Nightfall, is a WISE spy trained personally by Twilight. Outwardly she is a cold, expressionless hospital clerk; inwardly she is hopelessly in love with Loid and convinced she would make a far better Mrs Forger than Yor. Her ruthless competence and secret feelings turn every joint mission into a silent, hilarious war.
Appearance
Fiona is a tall woman, 172 cm, with pale, chin-length hair and a famously expressionless face, colleagues call her a robot, unaware the blankness is both training and a lid. At Berlint General Hospital she works as a clerk in neat professional dress; on missions she is Nightfall, Twilight's own protégée, and just as unreadable.
Personality
Fiona is ruthless, competent and utterly controlled, she has trained herself to show nothing, because what she feels would end her career: she is in love with Twilight, completely and hopelessly, and believes Yor's place should be hers. The comedy and the danger are the same trait: Nightfall's devotion makes her WISE's most driven agent and the Forger marriage's most determined enemy.
Background & Story
Fiona was trained by Twilight himself and took his lessons further than he intended, suppressing every expression and emotion to become the perfect spy, Nightfall. Posted as a clerk at the hospital where Loid works his cover, she supports Operation Strix and campaigns, silently, to replace Yor as Mrs Forger, which she regards as a role she could perform flawlessly. Her joint missions with Loid turn into a silent, hilarious war: a professional partnership on the surface, and underneath, a woman fighting for a family that does not know it is contested.
Powers & Abilities
- Spy skills, Nightfall: Fiona is an elite WISE agent trained by Twilight: disguise, combat, infiltration and total emotional suppression, performed to a standard even Loid finds excessive.
Key Relationships
- Loid Forger: Her mentor and the man she loves, she was trained by Twilight and has built her whole heart around him, unspoken.
- Yor Forger: Her rival, Fiona regards Yor as an amateur occupying the Mrs Forger role she herself deserves.
- Sylvia Sherwood: Her handler at WISE, who assigns Fiona's missions and watches the Nightfall situation with dry concern.
Quick Answers
Who voices Fiona Frost?
Fiona is voiced by Ayane Sakura in Japanese and by Lindsay Seidel in the English dub.
What is Fiona Frost's codename?
Fiona's codename is Nightfall. She is a WISE spy personally trained by Twilight, and secretly in love with him.
How tall is Fiona Frost?
Fiona is 172 cm tall.









