black as the ace of spades vs darkling

black as the ace of spades

adj
  • Utterly black; pitch-black. 

darkling

adj
  • Dark; growing dark; darkening. 

  • Obscure; taking place unseen, as if in the dark. 

adv
  • In the dark; in obscurity. 

noun
  • A creature that lives in the dark. 

  • Darkness 

How often have the words black as the ace of spades and darkling occurred in a corpus of books? (source: Google Ngram Viewer )