The King of Pain is derived from a Victorian era San Francisco man who made a fortune selling lineaments and ointments, before getting into gambling debt and committing suicide. Neil Gaiman included his version in the Sandman The Sandman #31 – Three Septembers and a January where he acts of Desire of the Endless‘ minions, tempting the Emperor of the United States.
Writer John Ney Reiber used him in the mini-series Mythos: The Final Tour where he acts as the manager for rock star Adam Case, which he wants to bring about the end of the world.