In 2000, Banner and the three Hulks (Savage Hulk, Grey Hulk, and the "Merged Hulk", now considered a separate personality and referred to as the Professor) become able to mentally interact with one another, each personality taking over the shared body as Banner began to weaken due to his suffering from Lou Gehrig's disease. During this, the four personalities (including Banner) confronted yet another submerged personality, a sadistic "Devil" intent on attacking the world and attempting to break out of Banner's fracturing psyche, but the Devil was eventually locked away again when the Leader was able to devise a cure for the disease using genes taken from the corpse of Brian Banner. In 2005, it is revealed that the Nightmare has manipulated the Hulk for years, and it is implied that some or all of the Hulk's adventures written by Bruce Jones may have been just an illusion.