Since I haven't read the 'The Black Angel' short story, it's difficult to determine the exact main characters. However, based on the title, we can assume that there is likely to be a character who has an interaction with the black angel. There might also be other supporting characters such as those who are affected by the events that unfold due to the presence of the black angel. For example, if the story is set in a small town, there could be the town's mayor or a local priest who gets involved in the situation that the black angel creates.