If he did something awful, why would you consider explaining the reasons why you had to block him? Why give to him in that way? He most likely doesn't deserve a reason. You're being far too nice, imo, even though I don't know what he did exactly, but I am sure it wasn't good. I don't think it would have even been bad to ghost him either, if he did something so terrible. Do you even really want this person as a friend? Would you advise a good friend of yours to keep someone like him in her life?? If it were your own daughter, would you advise your daughter to befriend someone who was a jerk?