Relationship identification

Relationship identification is the ability to sense the relationships, connections, and bonds between people.

Marcus (Twilight)
Marcus has the ability to recognize the types of relationships between people and their strong and weak spots. He usually shares this information mentally with Aro by touching his palm which is useful when Aro specifically wants somethign as he can use Marcus's power to determine who his enemies are and how close they are bonded to one another. He can also see if someone's loyalty is weaker than someone else's or if a new bond is being formed.