Corin

Corin is a female vampire member of the Volturi guard, whose first appearance was in the vampire index in the back of Breaking Dawn. She was also listed as not being mated. She is one of the nine permanent members of the Volturi guard and therefore wears their darker grey cloak.

History
When Corin was invited to join the Volturi, she was already a vampire (leaving her creator). She became a member of the guard around the time Didyme was killed. Aro hoped that she could help Marcus recover to some degree from the loss of his wife, but when Marcus refused to accept Corin's gift to ease his pain, Aro found that her gift was more useful to console the Volturi wives. Corin then spent most of her time associated with the wives, and is also the reason why they never leave the tower, as mentioned in Breaking Dawn.

In the Volturi, Corin's main responsibility is to protect the wives of Aro and Caius, Athenodora and Sulpicia. However, she doesn't guard them so much as ease them into complacency while other, while more physically imposing guards do the actual job of protecting the wives. The wives are so closely guarded that they have become virtual prisoners in Volterra. However, Corin's ability keeps them satisfied with life.

Aro also instructs Corin to use her gift on Chelsea, another high ranking member of the Volturi, making it nearly impossible for Chelsea to leave the Volturi, because of its drug-like side effects. Though Marcus has repeatedly refused to allow Corin to relieve his pain over Didyme's murder, Caius frequently exposes himself to Corin's gift between punishing expeditions and battles.

Breaking Dawn
In Breaking Dawn when Irina reports to the Volturi about an immortal child, an illegal creation, being created in the Cullen family, the entire Volturi coven departs to destroy the child, only to later find out that she is actually a half-human half-vampire hybrid.

Since the entire Volturi coven travels to Forks for this act, it is no doubt that Corin is among them.

Addictive contentment
Corin is gifted with the supernatural talent of inducing in others feelings of contentment for his or her situation. Her talent can be comparable to that of Didyme's "aura of happiness"; although rather than bringing out the positive feelings of happiness and joy, Corin instead brings out feelings of contentment and ease in a person, despite his or her situation. There is a drug-like side-effect to her gift to those who experience it often, as they may begin to feel unwell and uneasy without it.

Although it is not explained whether this gift is mental or physical, by the way it works it may be assumed to be a more physical gift, working similarly to Jasper Hale's empathy.

Appearances

 * Breaking Dawn