Isiah is not strictly human. His physiology is vastly different from that of a human. He has two stomachs, one designed expressly to digest blood. His bones are stronger, and he possesses more muscle tissue than the average human. The effect of this is obvious. Isiah is faster and stronger than most humans. His deep purple eyes give him excellent night vision, and his nails are as sharp as any razor. These abnormalities make him especially good at hunting, and fighting in general.
Isiah has the ability to heal wounds in a matter of minutes, which also contributes to his considerable longevity. A downside to all these abilities is that Isiah cannot step in sunlight during the day, or his flesh will burn and blister, leading eventually to death. No matter what, six hours in sunlight will render him dead.
Other than this, the only way to kill Isiah for good, is to destroy his brain or heart.
Along with his other abnormalities, Isiah is possessed by the Red Thirst. This is a key aspect of his species and comes upon him for four days every month, where he is filled with the desire to kill and drink the blood of a human. With his “gifts” He is amazingly good at this. It does not matter what sex or race the human is, so long as the life blood pumps through his veins.
Isiah's love in life is music. When the thirst has not consumed him, he can often be found (by night) curled up in the corner of a bar, a glass of scotch by his side, with his violin nestled in the crook of his neck. This instrument is a Stradivarius, acquired sometime in the 16th century by Isiah during his journeys across Europe.