Complex sentence: A recurring adversary of the superhero Batman, Zsasz is a sadistic serial killer who carves a tally mark onto himself for each of his victims, and he belongs to the collective of enemies that make up Batman's rogues gallery.
Split into simpler sentences: A recurring adversary of the superhero Batman, Zsasz is a sadistic serial killer who carves a tally mark onto himself for each of his victims. The character belongs to the collective of enemies that make up Batman's rogues gallery.