Not much is given on this mysterious figure so his personality is based only off of speculation. However, Mr. Gribbs did state that he liked his victims "kicking and screaming" which may hint to a sadistic nature. In contrast to this he apparently saved Zoe from a security guard and did not harm Zoe and in fact seemed drawn to her.
The enigmatic figure known as "David" makes an appearance in the first issue where he phases his fingers through a students head and out the front of their forehead and eye sockets. This causes the student to bleed profusely and even his eyeballs to pop out of his head. It is revealed that the student died from the injuries inflicted on him. He later makes an appearance when Zoe is about to be raped by a security guard. He kills the guard in the same bloody manner this time exploding his entire head and splattering Zoe with the gore. He then reaches for her but disappears when she calls his name. He shows up again while Mr. Gribbs is torturing Abraham with the evil man introducing him as Abraham's son.