Jaster tends to keep to himself as much as he can, and talks about himself even less. Jasters default reaction to most things is to respond to it in anger, though he attempts to control himself as best he can, though all he will say publicly of it is that is was due to his upbringing and how he was trained to be. However, he has never been too ashamed to let people know of some aspects of his past, that he had burned towns without remorse and many other things most would be loathe to admit to. He also has no faith in higher powers, feeling the Light, Elune and the Dragons have all failed in their charges to protect the world of Azeroth or are too weak to keep doing so, feeling only Mortals have a chance to fight for it's safety, and only Mortals have a chance to do what he hopes, which is destroy the Burning Legion.
Jaster also has a white kitten that follows him every where, despite his disdain for the animal, he can't seem to rid himself of it.
Jasters appearance is also something of question, one of the few people who have known him for some time, Kaash, has remarked that in the 20 years they've known each other, Jaster has not seemed to age at all, looking to be the same black haired man, in his late 20s. However, he has gained one notable change in recent times, which is a scar along his right hand's palm, and a matching one along the inside of the hands fingers, which he often looks at, while opening and closing his hand.