Marcus

Marcus is a vampire from Twilight.

Abilities
Relationship Identification: 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 something 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.

He can identify bonds between several people at the same time.

When Marcus first encounters Bella Swan and Edward Cullen, he is surprised by the intensity of their relationship.