Complex sentence: Razin'The Dead', the first of Skully's series which has been credited with creating the gothabilly sub-genre and established The Phantom Cowboys as one of the key groups associated with that style.
Split into simpler sentences: Razin'The Dead', the first of Skully's gothabilly series which has been credited with' creating' the gothabilly sub-genre. It also firmly established The Phantom Cowboys as one of the key groups associated with that style.