Alistair

Alistair is a vampire.

History
Alistair grew up in England during the turbulent reign of Edward II, considered the weakest of the Plantagenet kings. Alistair's father was one of the barons who continually fought against the King's attempts to limit the power of the British Peerage. Throughout Alistair's youth, his father and older brother were embroiled in conspiracy after conspiracy as they tried to protect the rights of aristocracy and to gain a place of preeminence over the other barons.

He lived quietly at the family's country estate with his mother and sisters. He had no interest in his father's schemes, he preferred to hunt for sport and was considered the best hunter in the county. Also an avid falconer, keeping many birds and training them being hsi favorite pursuit.

His father secretly formed an alliance with two other barons after the banishment of the king's favorite counselor. Alistair's brother was supposed to get a place in the counselor's position. However, after multiple betrayals on all sides, his brother was implicated in a plot to overthrow the king, and he and a few others were executed for treason. The charges were falsely created by another powerful aristocrat with an agenda that differed from Alistair's father's.

His father became increasingly distrustful of the other barons and eventually became obsessed with vengeance and sought aid of the darkest forces of the occult while the rest of the family completely withdrew from society. Alistair planned to take care of his sisters if they remained unmarried for his brother's fatal mistake. One night, Alistair's father brought him into the secret tunnels of London, where many minor aristocrats were gathered. His father had planned to set him on the throne of England and swore Alistair would be the next Charlemagne. Shortly after explaining this plan, a man called Astaroth arrived. He didn't know that Astaroth was a vampire who had agreed to change Alistair into a vampire under his father's wishes. After giving him a few pointers, he bit Alistair.

When his transformation was complete, Alistair slaughtered most of the peasants captured for him to feed on. After he was satiated, his father entered the cellar to explain the upcoming steps of becoming a vampire, but Alistair was too furious to listen and shoved him out of the way, accidentally killing him. He escaped the tunnels and ran back home, only to find his entire family gone. In a burst of insight, he realized that his father had given his family to Astaroth in exchange for his immortality. Totally devastated, he tried to seek comfort with the falcons, but they flew away in fear.

Alistair left civilization that night and avoided all contact with humans, except when he hunted, and mistrusted everyone and everything that had to do with authority figures with a sense of paranoia.

Powers and Abilities
Alistair's ability falls into the tracking category; he feels an elusive pull towards his target. However, his power is less efficient as it takes time for him to determine his target's location and he may never be able to catch up if the target is on the move. The one difference his power has from other more pronounced trackers is his ability to track an inanimate object. He seems to be able to ignore the pull if he wants to, as Bella pointed out that he could use it to run in the opposite direction from Demetri.

Source

 * Twilight Saga Wiki: Alistair