AZ Fell (Good Omens AU) [COMPLETED]

Once upon a time ago AZ Fell was just a young philosopher, he loved reading and writing, he had a best friend named Anthony JC. One day they go missing, where did they go you may ask? Many years pass, thousands per say, an angel and demon now live on earth, Aziraphale and Crowley, they look very familiar but where have they been seen before? And what exactly happened?