Blake was the play mate of Ninten in their younger years, because of their mutual love for torturing others and making demons miserable. They took great pleasure in terrorizing the city, but one day they got into an argument about who was scarier (silly I know, but they were seven) . Blake foolishly slandered Ninten's mother Josephine, which caused Ninten to transform into his evil counterpart, Dark Serpent. Blake was terrified and angrily accused Ninten of trying to kill him and swore revenge. They never spoke again.
Two years later Blake's younger sibling, Elvira was born. At the age of fifteen, Blake joined the Chaos Causers, Russian Sector. At twenty he was made head of the Earthquake and Blizzard Division.
When he turned eighteen, he joined a secret league that was devoted and determined to revolt against Lucifer, and take over hell. It seemed he hadn't forgotten "the incident" and was planning to act on his threat. He went thru the enrolment process and received that "Mark Of Flames" on his neck and left forearm (Voldemort is such a copy cat!).
When he was sent on a mission, he let his cronies in thru a crack in the space-time continuum and then abandoned his position. He and his crew then set out, searching for Ninten to insure no heirs were available to take up the thrown when they were rid of Lucifer. The throne of hell would then be empty and there would be no choice but for Lucifer's adviser to rule until the king was well. They had also eliminated that possibility by poisoning his mother, Rhiannon at a particularly wild extravaganza, leaving the crown of bones to Blake, her eldest.
Blake left when Elvira was ten and he never saw her again, until he witnessed her staring cow-eyed at a flame headed boy, who he later found out was called Claus and that he was a mortal. He was livid and then swore to kill him for supposedly "tainting" his sister.
PS: When he saw Ninten, he burst into hysterical laughter.