Some of the dark personality traits include narcissism, compulsion, paranoia, codependency, and passive-aggression. People have these and other dark characteristics to varying degrees, but what is important is to understand what tendencies you have and how to deal with them effectively. This is something the great leaders can do - effectively understand and deal with their dark characteristics. When they don't understand or do not effectively deal with these dark tendencies, they are ineffective leaders, they lose their following, influence, and power, and they do harm to the organization.
REAL LIFE APPLICATION: Discuss a leader that you know that has one or more of these dark personality traits. How does this leader handle her/his dark trait? Is it obvious to others that the leader has this trait? If you were this leader, what steps would you take to ensure that you deal with this dark trait effectively?