Repulsive magnetism

Illusionary repulsion is a special ability to implant a revolting thought into another person to repel him/her from the user.This power can break through a mental shield because it physically changes the sense of smell. Fred is so far the only vampire to utilize this skill.

Description
Fred can use it to project a thought into those around him to make them think that he smells repulsively to drive them away. Bree always sits behind him to avoid trouble. As he grows older, he learns to make others feel repulsive even by thinking about him, making him almost "invisible" to them. This power is most likely to create the illusion of disgust, and repulsion is an innate instinct all organisms have for things that seem unclean, inedible or infectious.

Fred was able to evacuate a whole basement full of vampires with his revulsion. He also used this gift to avoid the fight between the Cullens and the newborn army in Eclipse, becoming "invisible" for at least 20 minutes while he escaped before the other newborns approached the Cullen family.

At some point, Bree notices that when she's really close to him, she doesn't feel the repulsion. It's unknown if "Freaky Fred" (see Fred) can do this on purpose or if it's something natural, that if you get really close to him, you can't feel it. (For example, this could benefit him and whatever mate he may find).

Limitations
It is highly likely his power can be blocked by Bella Swan's mental shield.

Similar abilities
This power can be considered similar to Renata's protective shield, and Jane's illusion of pain: Renata is able to project a thought into her attacker's mind to make him go another way, and Jane can inflict an illusion of pain into her target.