He doesn't appear to be like other vampires as he has the ability to understand and share the feelings of another which would explain why Skulduggery Pleasant calls him an 'empathy Vampire'. He could feel Susan Dewick's doubt and uncertainty.
He also uses Symbol Magic which he carves into books so that the readers will, in the words of Sebastian Fawkes "care about your characters so much that when those characters die they are traumatized far past the point of tears". There are also other symbols in the words, in the sentences, and the paragraphs that act upon the readers subconscious and make them buy multiple copies of the books and they feed into Sabastian keeping him young.
He was a tall, muscled man who walked bare-chested. He was bald. As he was attending The horror writers' Halloween ball, he was wearing a white toga as a costume