The character has a second brain that hinders his thought processes. This brain has 1d4 mental mutations of its own (half of which should be defects, round up), which should be kept secret from the player until an opportunity to discover them comes about during play. This second brain may have an entirely different personality and motives than the character, and may try to foil the character’s actions at inconvenient times. This is up to the ML’s discretion. This “Hyde” brain may attempt to take over the mutant’s body, as the mutation possession, once per month for a duration of 24 hours.