1. Following the Fansproject lore for Colossus here, as well as some of the implications made by Vangelus’ skits in his review for the set. Intimidator is, according to the lore, a ‘Combiner Killer’, designed specifically to fight and destroy OTHER combiners.
2. According to that same lore, Colossus’ gestalt mind is held together and controlled by Explorer, while Intimidator is essentially Diesel-dominated. While Diesel keeps control through the fear the other members have of him, Explorer is constantly struggling to keep the reigns on a raging, self-destructive hate-beast, as the flaws in the 1st generation gestalt interface result in a psychotic gestalt mind.