When Alice, Bella and Edward go to the Volturi, there is someone named Felix. Who is he???

Felix is part of the Volturi Guard. His purpose, to protect Aro. I don't think he has an special powers, although he is very strong I don't really consider that a power.
In New Moon he was ordered, along with Demetri, to bring Edward back to Aro and that's when Bella saves him from getting out into the sunlight and door then Felix and Demetri see her and bring her along with Alice as well to Aro.

hope this helped =)

he's a volturi guard.

Felix is one of the Volturi. he specilizes in Tracking people but he cant track bella because of her mind and the way her mind works with the shield. Felix is a tracker,like james,but a much better tracker.

he's a tracker

Felix is a member of the Volturi Guard. He is described as a very tall, very strong vampire, black haired,and skin that is slightly olijf-, olijf toned.

Felix has no power, however Aro, who i assume u are familiar with, wanted Felix in his guard becuase Felix is considered a "defensive" vampire becuase of his exceptional fighting skills and immense strength.

Unfortunately Felix's complete history remains a mystery unless Stephenie Meyer decides to write it...until then we will not know much about Felix.