As an anime fan, I have picked up the widespread habit of looking for the similarities among different characters of different series. Since this is a Sylphiel shrine I naturally thought I'd include a bit about other anime characters that have personalities or appearances that resemble Sylphiel's.
» the slayers
I seriously doubt you can have a look-alike section without mentioning Miwan from NEXT. Both Miwan and Sylphiel appear so much alike it is as though they had been separated at birth and are really long-lost siblings. They each have the ultra long hair, though different shades, with the same wide set green eyes. Their personalities are similar as well for they are kind-hearted and gentle and would do anything -- and I mean anything -- for their loved ones.
» cool devices
When I first saw Ai, I did a complete double take. She looks Exactly. Like. Sylphiel. So much that it is scary, especially since Ai is a character in a hentai film. You can only tell it's not Sylphiel because Ai has pink hair and violet eyes. It is safe to say though they share more than looks for Ai is very shy and soft-spoken but deep within she has a hidden wild side to her that Sylphiel has also shown on more than one occassion.
Before Miwan, the first Sylphiel look-alike that came into my head was actually Kikyou. Although their religions are different, both women are shrine maidens and protect a sacred artifact of some sort, i.e. the Shikon no Tama and the Bless Blade. They're also very similar in appearance with long dark hair and looks of forlorn sadness on their faces from the tragedies both have suffered in life.
» yu yu hakusho
Yukina and Sylphiel do not share a physical resemblance, but their personalities are very similar. They are both healers, are very sweet natured, and have been pretty much sheltered their whole lives, which makes them naive to the ways of the world. Yukina has an unbreakable love for her brother as does Sylphiel with her father, showing how much family means to them.
» tenkuu no escaflowne
At first it is hard to affiliate Sylphiel with Millerna but they have more in common than one would believe. Both come from well-to-do families and are often received as obstacles when it comes to the heroine's love interest; though Sylphiel is not as vocal about her love for Gourry as Millerna is with Allen -- notice the blonde swordsman affiliation.