The comic strip format disguises the horror to a degree but Rohr avoids total cartoonery so there's still a sense of realism. What little humour he depicts is distinctly macabre and tasteless. Nevertheless, in the best traditions of Hollywood horror, it skilfully constructs an sense of genuine suspense regarding Marc's fate as he is drawn into the Sultan's web.
I would welcome information about him from readers.
Have a look also in the GMBA2 archives for examples of his work (link in sidebar)