Obstacle Character’s Unique Ability • [Variation] • The item that makes the Obstacle Character uniquely able to pressure the Main Character to change • The reason the Obstacle Character is able to carry half of the Subjective Story is his unique suitability to take the opposite position to the Main Character in regard to the Crucial Element of the story. The Obstacle Character’s Unique Ability gives the Obstacle Character a power which no one else in the story has: to be able to pressure the Main Character to change his very nature.

From the Dramatica Dictionary