Void is the leader of the Nightmares in the Dreamkeepers graphic novel saga. Despite being summoned via virgin sacrifice in Volume 1, it seems he has yet to return to full power.
He, along with the rest of nightmares, are demonic creatures that said to be the primary causes of nightmares that suffered by mankind. It was said that whenever humans are sleeping and having dreams, their pure minds can sometimes see the Dreamworlds. In doing so however, they became vulnearable with these foul creatures. In spite of this, this matter doesn't truly a serious problem as they have their counterparts within the Dreamworld. These counterparts called Dreamkeepers, which taking form as anthropomorphic animals with immense powers, which their appearance and powers are depends on person themselves.