"Gusters are elves with the special ability to control wind. At Exillium, there is at least one, and their ability is depicted on a pin illustrating a tree blowing in the breeze. Some of the things a Guster can do by manipulating the air are forming tornadoes, slamming and pinning people into the ground (as seen by Wylie's recount of his capture), and parting water (as the Neverseen's Guster, Trix, had done to enter Nightfall)."
Sir Sarak grew up in the nobility and was an oblivious fool to the cracks in Elvin society until he was kidnapped by a group of Human terrorist and he saw how Elves instead of leaving humans to their own devices like they had in the past they should help them repair there broken ways and let them into the intelligent creature sect. He saw that humans are not as foolish as elves thought they were and that they should have rights as well. His parents were the first notable Physicians of the Elvin world they were snobby rude and terrible people.
He is a kind person but they can get irritated and plot terrible things when they are manipulated to do something or be part of something against their will but overall they are a pretty decent person.