Sylphiel demonstrates the stereotype of a classic demure beauty. She's very beautiful and pulls it off with style in her traditional shrine maiden robes along with her long hair and natural beauty. Her frame is small and delicate and her appearance and behavior are of a renowned noble lady. Compared to the other Slayers females, save for Filia, she is more reserved and doesn't resort to wearing very revealing clothing such as Naga and Martina, and isn't cute and spunky like Amelia or Lina.
x above the neck
First things first, Sylphiel has gorgeous hair! It's straight and ultra long, reaching to the small of her back, and is black in color that usually has a blue or purple-ish sheen to it unlike the unnatural hair colors most anime women have. Her face is always gentle and caring in the company of family and friends but it takes on a more somber look during times of sadness. Her skin is peachy and healthy looking; no blemishes, wrinkles or scars demising her youthful and innocent appearance. The most expressive feature on her face though are her eyes, which are bright green in color. You can always tell what is going on through Sylphiel's mind just by looking into her eyes for she is more empathetic than others. They're what make her face stand out the most since she doesn't have any distinguishing features or wears jewelry.
Throughout her appearances in Slayers, she is seen wearing the traditional robes of a shrine maiden of Sairaag. They are elaborate clothing but more modest for her "hour-glass" figure. Purple, gold, and green are the main colors they're composed of and are most associated with her. The colors may signify her profession as a healer for they are associated with spirituality and peace, but the purple may also mean her social status, since in Medieval times shades of purple were only worn by royalty and high-ranking nobles. A purple tunic is fastened at the collar by an old-fashioned front panel adorned with gold piping, a red amulet, and jewels. Many argue that the amulet belonged to Sylphiel's mother but we see a similar panel with an amulet worn by other characters of religious upbringing, an example being Filia. Resting on her shoulders are epaulettes trimmed with gold tassels though they don't serve a significant purpose but give the whole outfit a uniform feel to it. Adding a final touch is her long black and green cape, which falls to her ankles.
Her trademark purple gloves always cover her hands. They appear to be thick, most likely made of cloth and the cuffs are detailed with more gold piping. It's very rare to see her without them on, unless she is cooking perhaps. The main item we see her carrying in her hands during the series is the round scepter her father gave to her when she became a shrine maiden that she uses to enhance her spells.
Sylphiel has quite the long legs though she is of average height, coming in third after Naga and Filia for being the tallest Slayers girl. She wears lavender tights made of a thin material that go all the way down to her feet where the strap attaches on the arch of her foot. Over that are a pair of purple shorts with the gold piping around the borders and sides. Also a black belt is used as an accessory but it is difficult to see due to the front panel of her outfit.
For shoes, Sylphiel always wears tall purple boots detailed with gold piping made of a light-weight material that extend up her calf, ending around just below her knee.