One of Wiesel's strengths is that his characterization of Elisha is truly complex. He does not construct characters that are either "sinners" or "saints." Wiesel's view of human nature is complex enough so that his characters are more human than anything else, capable of great horror and equally striking benevolence.
It is in this light where I think that Wiesel does not construct Elisha to be either a prophet or a force of condemnation. He makes him out to be an individual struggling with how to reconcile what he experienced in the Holocaust with how he lives. For his part, Elisha believes that the way of the terrorist group makes some sense. It helps to provide meaning and structure to his life which, arising from the ashes of Buchenwald, lacks it. Yet, Elisha also understands the difficulty in having to execute Dawson. He struggles with his mission and the repercussions of such an action. It is here, within this struggle, where Elisha transcends characterizations such as "prophet" or "angel of death." Rather, he is a human that struggles with the capacity to do evil and the reservoir to be benevolent. Perhaps in not making Elisha diametrically opposed and binary, Wiesel is suggesting that individuals who emerge from conditions like the Holocaust have a variety of paths and doors to take and to open in defining their own consciousness. These choices are what makes them, moving beyond labels, beyond reductionist methods of characterizations. In this light, Elisha faces his own crucible of choice that will play a role in defining him. His choice represents the capacities that define who and what human beings are.