Satan is the Avatar of Wrath, the forth of the Seven Rulers of Hell. He is the fourth out of seven demon brothers, although technically he is the last to have been born. Satan was, at one point, part of Lucifer. It was during the Fall that he gained a separate body. Due to the circumstances surrounding his unusual birth, he hates Lucifer with great passion, although secretly it'd be more exact to say he hates being reminded that he's technically a fragment of his older brother.