Who is Felix Lodd from The Last of the Sky Pirates and what is their importance?

Felix Lodd is Rook's best friend. He is the son of Fenbrus Lodd. Varis Lodd is his brother. Felix is favored to be chosen as a Librarian Knight elect, so he is very disappointed when Rook is chosen instead. Though he does not tell his friend goodbye, Felix leaves his sword on Rook's bed for Rook to take with him on his journey to Lake Landing.