Sylphy is a servant and the first card obtained by Kaito.
Introduce herself as Demigod (Valkyrie).

Sylphy is very polite and obedient, although she is not above reprimanding her Master when necessary. If she can assist Kaito, she will gladly do so, and if her assistance is lacking, she takes it as a failing on her part, but cheers up very quickly upon receiving praise for her actions. When Kaito levels up, she is quick to congratulate and praise him for having done so. Overall, she has a bright and warm personality, and has stated that she is 'thrilled' that Kaito is her master. She also appears to hold some degree of romantic affection for Kaito.

Sylphy appears as a young, ethereal girl. Wears a white dress with blue borders around her chest and petal like patterns on the skirt, each tipped with a small blue gem. Her stockings and gloves are both white and edged with blue. She wears a long cape that reaches down to her knees, which is white on the exterior but a light shade of blue on the inside, and is also edged with a blue trim. Around her neck she wears a white and blue collar adorned with a blue gem. Her tiara, pauldrons, greaves, boots and armour are all silver. She has a pair of small wings that emerge from her upper back. Her boots are decorated with wings. Her hair is cyan, and done up in an odango style with wing-like accessories.